d e e p e r th a n in p a p ilio , a n d th e u n d e r p o in t o n ly is s p in o u s .
T h e su p r a - s c a p u la r a n d c o ra c o id b o n e s h a v e th e sam e
fo rm a s in p a p il io , v iz ., th e y h a v e a c e n tr a l rid g e , w h ich
e n d s in a n a c u te p o in t, a u d th e su rfa c e is ro u g h , a s in th e
o th e r b o n e s o f th e h e a d . T h e o p e rc u la r sp in e s h a v e n o
su c h r id g e p ro c e e d in g from th em . T h e h n in e r a l b o n e is
oval, a n d sm o o th e r th a n a n y o th e r b o n e s a b o u t th e g ill-
o p e n iu g o r h e a d .
I ’lie sp in o u s tip s o f th e in te ro s s e o u s b o n e s w h ic h a rm
th e d o r s a l fu rrow , a re tw e n ty - tw o o n e a ch s id e , a n d a re
a c u te a n d t r e n c h a n t, e x c e p t th re e o r fo u r a n te r io r one s,
w h ic h a re m o re o r le s s c om p o u n d . T h e sp in o u s s c a le s o f
th e la te r a l lin e c o r re sp o n d w ith th e d e s c rip tio n g iv e n o f
th o s e o f T r . p a p i l io , b u t th e c h ie f sp in e o f e a ch is la rg e r
a n d m o re ti'e n c h a n t th a n th e la te r a l s p in e s o f a n y T r ig la
o f w h ic h I h a v e s e e n sp e c im e n s o r r e p r e s e n ta tio n s . In
p la te X V L , figs. 3 a n d 4 , th e s c a le s a r e tu rn e d u p s id e d ow n ,
a n d th e y b e lo n g to th e le f t s ide o f th e fish. T h e y c o r re
s p o n d in n um b e r w ith th o s e o f p a p ilio , b e in g fifty-five.
T h e la te r a l lin e fo rk s o n th e c a u d a l fin very rem a rk a b ly .
T h e s c a le s o f tb e b o d y , w hen in s ilii, p r e s e n t sm a ll
rh om b o id a l o r n e a r ly re c ta n g u la r d isk s . W h e n d e ta c h e d ,
th e y h a v e g e n e ra lly a d ila te d , fa n -s tre a k e d , five o r s ix -
lo b e d b a s e , co n c a v e ly c u rv e d s id e s , a n d a h e a r t- s h a p e d ,
a p ic u la le d d isk , w ith an a c u te lin e o r rid g e from th e ap e x
to th e c e n tre . I n som e p a r ts , n e a r th e la te r a l lin e for in s
ta n c e , th e s c a le s a re o b liq u e , a n d h a v e more e lo n g a te d
tip s , a n d o n th e b a c k some h a v e two p o in ts . T h e c o n c e n tr
ic lin e s o f s tru c tu r e a re v e ry in d is tin c t, e sp e c ia lly n e a r
th e ed g e s o f th e s c a le , w h ich a re n o t to o th e d , th e ir s tru c tu
r e b e in g a p p a r e n tly c ten o id .* T h e s c a le s o f T r . p a p
i l io a re d e s c r ib e d a s b e in g n e a rly lik e th e above , b u t w ith
two p o in ts ; th o s e o f p h a lc en a a n d sp h in .x h a v e ro u n d e d ,
n o t h o llow s id e s . J u d g in g from th e fig u re o f p a p ilio , in
th e H i s to i r e d e s P oissons, th e sc a le s o n th e flan k s o f p le u r a -
c a n ih ic a a re sm a lle r th a n th o s e o f a n y o f th e s p e c ie s w ith
w h ic h we h a v e c om p a re d it.
T h e f ir s t d o rs a l is l e s s r o u n d e d , a n d h a s a m o re p a ra b o lic
o u tlin e th a n th a t o f p a p il io . T h e sp in o u s r a y s a re n o t so
ir r e g u la r a n d s u d d e n ly b e n t. T h e th ird sp in e is th e t a l l e
s t, a n d th e firs t two a re s e r r a te d in f ro n t b y a s in g le row
o f c om p re s s e d t e e th . T h e la s t r a y s o f th e s e c o n d d o rs a l
a u d a n a l a re d iv id ed to th e b a se .
T h e sp e c im e n s h a v e b e e n g re a tly in ju r e d b y th e d e te r io r
a tio n o f th e s p i r i t in w h ic li th e y we re im m e rs e d , so th a t
th e fin -in c ra b ra n e s h a v e n e a rly p e rish e d , a n d th e tin ts o f
c o lo u r a re q u ite lo s t ; b u t th e r e a p p e a r to b e som e tra c e s
le f t o f a b la c k sp o t on th e fo u rth , fifth, a n d s ix th s p in e s o f
th e f ir s t do rsa l.
T iie a ir -b la d d e r is o f a n ov a l form, a n d o f th e s iz e o f a
sm a ll p e a . I t is div id e d fo r n e a rly a th i rd o f its le n g th
in to two c o n ic a l lo b e s , o n e o f which is o b tu s e , th e o th e r
m o re p o in te d . A t th e o th e r e n d o f th e b la d d e r th e r e is a
s h o r t, n a rrow , c y lin d r ic a l p ro je c tio n , w h ich d iv id e s th e two
la te r a l m u s c le s th a t frin g e th e v iscu s.
T h e sp e c im e n s a re s ix in c h e s lo n g , o f w h ic h th e h e a d
fo rm s e x a c tly ,o n e - fo u r th .
•* By rnisliike, a second spinons scale from th e la tera l lin e v
instead of one o f th e smaller ones from the flanks.
T h e a ir -b la d d e r is in l e n g th 0 '3 1 in c h e s , a n d in b r e a d th ,
0.22.
H a b . S id n e y Co v e , P o r t J a c k s o n .
D a t n ia ? c a u d a v it t a t a . R ic h a rd s o n .
C h . S p e c . 1). dorso late i-ih n sq n e m a c n lis p a r v is c r e h r is
n ig ro -fu s c is a spe rsis ; p in n d d o rsi g u t ta td e t a n tic è a d
n ia rg in em m a c u lo n ig ro n o la td ; p in n d c a n doe u tr in q u e
n ig r o fa s c ia ta .
R a d i i :— B r . 6— 6 : D. 13]9 ; A. 3 |8 ; C. 1 3 |; P . 1 5 ;V . 1 , 5 .
P la t e X V H I ., f ig s . 3 , 4 , 5.
T h i s fish d iffe rs from th e ty p ic a l D a tn ia a rg e n te a , in
h a v in g m ore s le n d e r d o r s a l sp in e s , a n d a p o ro u s low e r
j a w ; a n d from th e g ro u p o f T h e ra p o n , D a tn ia , P e lâ te s
a n d J/e /o fe s , in its a ir -b la d d e r b e in g s im p le , a n d n o t d iv
id e d b y a naiTOw n e c k in to tw o p a rts . T h e a ir -b la d d e r
o f o u r sp e c im e n is a n in c h a n d a q u a r te r lo n g , v e ry o b tu s e
a t o n e e n d , a n d ta p e r in g to a n a c u te p o in t a t th e o th e r.
I t s th ic k e n d is m a rk e d b y two sh a llow furrows, p ro d u c in g
th r e e s lig h tly p rom in e n t ro u n d e d lo b e s. I t s c o a ts a re
n a c ry , a n d ve ry d is tin c tly fib ro u s , th e o u te r la y e r o f fibres
e n c ir c lin g th e v is cu s tra n sv e rs e ly , a n d th e in n e r o n e lo n g itu
d in a lly . In th e c o n d itio n in w h ich th e sp e c im e n was,
h a v in g b e e n lo n g m a c e r a te d in s p ir its , th e s e fib re s s e p a r
a t e d b y a to u c h . T h e a n a l orific e is sm a ll, with p la ite d
lip s , a u d im m e d ia te ly b e h in d i t th e re is a in im ité tum id
p a p illa , n o t ra is e d a b o v e tb e n e ig h b o u r in g le v e l, b u t
b o u n d e d p o s te rio rly b y a d e e p s in u s . T h i s p a p illa is
p ie r c e d b y a n orific e , wh ich p e rm its a b r is tle to p a s s in to
th e a b d om e n , b u t th e in te s tin e s h a v in g p e r ish e d , th e origin
o f its d u c t c o u ld n o t b e a s c e rta in e d .
T h e h e ig h t o f th is fish is eq u a l to o n e - th ird o f its to ta l
le n g th , b e in g p ro p o r iio n a b ly le s s th a n in D . a rg en tea .
T h e th ic k n e s s o f th e b o d y is a b o u t a th i rd o f th e h e ig h t,
a n d th e h e a d fo rm s a b o u t a fo u rth o f th e whole le n g th .
T h e p ro file a s c e n d s o b liq u e ly , from th e r a th e r a c u te sn o u t,
a lm o s t in a s tr a ig h t lin e to th e n a p e , w h e re it ro u n d s o ff
in to th e d ô rs a l lin e , w h o se sum m it is a t th e fo u rth o r fifth
d o rs a l sp in e , a n d o iip o s ite to th e a tta c hm e n t o f th e v e n tra
le .* T h e e y e s ro u n d , m o d e ra te ly la rg e , a n d c lo s e to
th e p ro file , w ith o u t in te rfe rin g with i t , a re n e a r ly a
d iam e te r o f th e o rb it a p a r t from e a c h o th e r. T h e jaw s ,
g ill-m em b ra n e , p r e o rb ita r , a n d th e to p o f th e h e a d , b a c k
to th e tem p le s , a re s c a le le s s . Two a c u te , smooth rid g e s
ru n from th e n o s tr ils to th e s c a ly su rfa c e o n th e h in d
h e a d , a b o u t a s d is ta n t from e a c h o th e r a s e a c h o f th em is
from th e ed g e o f th e o rb i t o f th e sam e sid e . A m e sia l
rid g e c om m en c e s an te rio rly , b u t s in k s to th e le v e l o f th e
sk u ll b e tw e e n th e ey e s, r e a p p e a r in g a g a in b e h in d th e s e
o rg a n s , a n d ru n n iu g we ll b a c k o n th e s c a ly n a p e . T h e
p o s te r io r fro n ta l is m a rk e d im m e d ia te ly b e h in d th e ey e b y
som e sh o r t, b r a n c h in g , e le v a te d lin e s , tu rn in g o b liq u e ly
o u tw a rd s . T h e s e rid g e s a re a ll sm o o th , a n d a re n e a rly
c o n c e a le d b y th e in le g um e n ts in tlic r e c e n t fish.
T h e in te rm a x illa r ie s a rc s c a rc e ly p ro tr a c tile ; b u t th e
m a x illa r ie s , e x c e p t a ve ry sm a ll co rn e r, c a n b e co n c e a led
‘ I n Da tn ia argentea, the ventrals are farther forward.
b e n e a th th e p re o rb ita r . T h e low e r jaw is p o r ro r a te d b y
tw o sm a ll p o re s o n e a c h s id e o f th e c liin t a n d th r e e c lu s te
rs o f s till sm a lle r o n e s o n e a c h lim b o f th e j aw , co n -
la ininB from five to e ig h t o r ten^m e a c h c lu s te n T h e te e th
a re d isp o s e d in p r e t ty b ro a d , d e n s e ly v ilb fo rm b a n d s o n
th e jaw s, d iv id e d a t th e sym p h y s e s b y a fin e sm o o It in e .
T h o s e o f th e o u te r row a b o v e a n d b e low a re su b u la te ,
a little ta lle r th a n th e r e s t, in c u rv e d a t th e tip s , a n d p r e tty
c lo se ly s e t. T h e r e a re n o te e th o n th e p a la te , v om e r o r
to n g u e . A few v e ry m in u te p a p illa i a re v is ib le o n th e
c h ev ro n o f th e v om e r, b u t th e r o o f o f th e m o u th is sm o o th ,
a u d w ith o u t p la its . , ,
T h e p r e o rb ita r , p r e o p e r c u lum , in te ro p e r c u lum , su b o p e r-
o tilum ,a n d s n p r a - a x illa ry p la te o f th e co ra c o id b o n e , a rc
a ll r e g u la rly s e rra te d o n th e ir ed g e s . I h e c h e e k , h a v in g a
sq u a rish , o r s lig h tly rh om b o id a l fo rm , a n d a h e ig h t e x c
e e d in g th e d iam e te r o f th e o rb it, is d e n s e ly c o v e re d with
sm a ll sc a le s. T h e s c a le s o n th e in te ro p e r c u lum a n d g ill-
co v e r a re la rg e r. T h e d isk o f th e p re o p e r c u lum is a n a r row
c re s c e n t, w ith th e u p p e r lim b lo n g e r th a n th e lower
o ne T h e t e e th o f th e low e r lim b a re ve ry m m u te , a n d
in c lin e s lig h tly f o rw a rd s ; th o s e o f th e u p p e r o n e p o in t
o b liq u e ly u p w a r d s ; a n d tow a rd s th e m id d le o f th e curve ,
th e y b e c om e s e n s ib ly la rg e r . T h e s e te e th , a s w e ll a s
th o s e o n th e o th e r o p e rc u la r p ie c e s , h a v e m le rv e nm g a c u te
fu rrow s ru n n in g a s h o r t w ay o n th e su rfa c e o f th e b o n e ,
b u t a ll th is is c o n c e a le d in th e r e c e n t fish, b y th e n a c ry
in te g um e n t. T h e o p e rc u lum is n o tc h e d a t i t s a p e x b y a
c re s c e n tic s in u s , w ith a c u te fla t tip s , th e low e r o f w h ic h is
th e la rg e s t. T h e r e a re from se v e n to te n o r m o re te e lh on
th e su p ra -a x illa ry p la te o f th e c o r a c o id b o n e , th e n um b e r
o f te e th v a ry in g in d iffe ren t in d iv id u a ls . A p a tc h o f s c a le s
e x is ts in th e m id d le o f th e p la te , th e r e s t o f i t s d isk b e in g
c lo th e d with n a c ry sk in . T h e s c a p u la is o b lo n g , sm o o th
a n d e n tire , b u t th e s u p r a - s c a p u la r b o n e is e n tir e ly cov e red
b y th e sc a le s , w h ic h do n o t d iffe r from th e o th e rs .
T h e sc a le s a re s tro n g ly c ilia te d , a n d p r e s e n t, w h en in
s i tu , a rh om b o id a l d isk . T h e la te r a l lin e is tr a c e d w ith in
th e u p p e r th ird o f th e h e ig h t, a n d p a r a lle l to th e b a c k , a s
fa r a s th e e n d o f th e d o r s a l, w h e r e i t m a k e s a s h o r t cu rv e
d ow nw a rd s , a n d p u r su e s its c o u rs e a lo n g th e m id d le o f
th e ta il. I t is c om p o s e d o f fifty-four s c a le s , e x c lu s iv e o f
some sm a ll o n e s o n th e b a s e o f th e c a u d a l, a n d th e r e a re
a b o u t tw e n ty row s o f s c a le s in th e v e r tic a l h e ig h t o f th e
b o d y . A fille t o f s c a le s ru n s a lo n g th e b a s e o f th e d o rs a l
a n d a n a l fins, sp r e a d in g m o re b ro a d ly o n th e j o in te d rays,
b u t n o t c o n c e a lin g th e sp in e s wh en r e c um b e n t.
T h e sp in o u s p a r t o f th e d o rs a l fin is m u c h a r c h e d , th e
fifth a u d s ix th sp in e s b e in g th e ta lle s t, a n d e x c e e d in g h a lf
th e h e ig h t o f th e b o d y . T h e sp in e s a re a lte rn a te ly r ig h t
a n d le ll, a n d d im in ish in h e ig h t from th e s ix th to th e la s t,
which is a s s h o r t a s th e th ird o ne . T h e i r h e ig h t a n d
th ic k n e s s v a rie s a little in d iffe re n t in d iv id u a ls . T h e
so ft ra y s a re ev en , a n d h ig h e r th a n th e p o s te r io r sp in e s ,
a n d th e l a s t o ne is d iv id e d to th e b a s e . T h e s e co n d
a n d th i rd a n a l sp in e s a re e q u a l to e a c h o th e r , a n d n e a rly
tw ic e th e h e ig h t o f th e f ir s t o ne , b u t a r e o v e rto p p e d
b y th e soft p a r t o f th e fin, w h ich is sh a p e d lik e th e c o r r e sp
o n d in g p a r t o f th e d o rs a l. T h e v e n tra ls a re u n d e r th e
m id d le o f th e p e c to r a ls , o r fo u r th d o r s a l sp in e . T h e
c a u d a l is sha llow ly c r e s c e n tic a t th e end.
T h e co lo u rs o f th e fish h a v e , d o u b tle s s , u n d e rg o n e c o n s
id e ra b le a lte r a tio n from m a c e r a tio n in sp ir its , b u t th e
s c a le s s till r e ta in a b r ig h t s ilv e ry lu s tr e , w ith lin e s c o r re
s p o n d in g to th e n um b e r o f row s . T h i s s ilv e ry h u e is
u n s ta in e d o n th e b e lly . T h e to p o f th e h e a d , b a c k , a n d
u p p e r p a r t o f th e s id e s , h a v e a b row n ish tin g e , a u d a re
th ic k ly sp e c k le d w ith d a rk e r b row n s p o ts , w h ic h b e c om e
g ra d u a lly e ffa c ed o n th e s id e s . T h e r e i s a d a rk m a rk u n d e r
th e ey e , a n d tw o o r th r e e row s o f b row n sp o ts e x is t o n th e
d o rs a l a n d b a s e o f th e c a u d a l. T h e u p p e r e d g e o f th e
so ft d o rs a l is m a rk ed a n te r io r ly b y a d a rk p a tc h ,* a n d a
b ro a d j e t - b la c k b a r c ro s s e s e a c h lio n i o f th e c r e s c e n t of
th e ta il o b liq u e ly . T h e r e a re a lso tw o b row n lo n g itu d in a l
b a r s in th e m id d le o f th e ta il.
T h e le n g th o f th e lo n g e s t sp e c im e n is s ix in c h e s .
H a b . H a rv e y R iv e r (fresh w a te r), W e s te rn A u s tra lia .
G o o d sp e c im e n s w e re p r e s e n te d to th e M u s e um a t H a s la r ,
b y M r. B y n o e , a n d a lso b y J . G o u ld , E s q ., th e a u th o r o f
th e O rn ith o lo g y o f A u s tra lia .
D a t n ia ? a m b ig u a . R ic h a rd s o u .
R a d i i ;— B r. 6 ; D . lOl— 1 1 ; A. 3 l 9 ; C . l o f ; P . 1 6 ;
V . I j 5 .
P la te X IX ., n a tu r a l siz e .
I h a v e h a d m u c h d o u b t as to w h e th e r th is fish s h o u ld b e
p la c e d in th e g en u s D a le s , o r D a ln ia . I t a g re e s w ith th e
g ro u p o f D a le s w h ic h h a v e tw o o p e r c u la r p o in ts , in th e
n um b e r o f d o r s a l ra y s , a n d in th e p r e s e n c e o f p a la tin e
te e th , b u t in g e n e ra l h a b it i t is m o re lik e D a tn ia , s tro n g ly
r e s em b lin g i t in th e s tr e n g th o f its d o r s a l a n d a n a l sp in e s ,
a n d in th e n um b e r o f r a y s in th e a n a l. T h e o n ly tw o
sp e c im e n s th a t I h a v e h a d a n o p p o r tu n ity o f e x am in in g
a re d rie d , a n d a rc b o th m u tila te d in th e c a u d a l fin, so th a t
I am u n a b le to d e s c r ib e th e form o f t h a t m em b e r, a n d c a n
give n o an a tom ic a l d e ta ils .
F o rm c om p re s s e d , th e th ic k n e s s o f th e b o d y b e in g
a b o u t h a l f th e h e ig h t, w h ic h is g r e a te s t a t th e c om m e n c e m
e n t o f th e d o rs a l, a n d a l ittle e x c e e d s o n e - th ird o f th e
le n g th o f th e b o d y , c a u d a l e x c lu d e d . T h e b a c k is m o re
a c u te th a n th e b e lly , a n d th e p e lv ic re g io n is fla t. I n
p ro file th e u p p e r cu rv e m u c h e x c e e d s th e v e n tra l o ne .
T h e s h o u ld e r is ro u n d e d , th e fa c e c o n c a v e , a n d th e d e s c e n t
o f th e p ro file , from th e d o r s a l fin, c o n s id e ra b le , th e m o u th
b e in g in th e low e r th i rd o f th e h e ig h t.
T h e le n g th o f th e h e a d e q u a ls th e h e ig h t o f th e b o d y ,
a n d th e t ip o f th e g ill-c o v c r is in th e lin e o f m id -h e ig h t.
T h e n a p e is c o n s id e r a b ly e le v a te d above th e s c a p u la r
reg io n s . T h e sm a ll ro u n d o rb it, h a v in g a d iam e te r o f
o n ly o n e - s ix th o f th e le n g th o f th e h e a d , is c lo s e to th e
p ro file , a n d its d iam e te r is o n e - th ird le s s th a n th e s lig h tly
c o n v e x sp a c e b e tw e e n th e ey e s. T h e a n te n o r a n d sm a lle r
n o s tr il is p la c e d m idw ay b e tw e e n th e e y e a n d th e tip o f
th e sn o u t. T h e lo p o f th e h e a d is sc a le le s s , a n d th e b o n e s
o f th e c ra n ium sh ow th ro u g h th e d r ie d sk in , b u t e x h ib i t
n o p e c u lia r s c u lp tu r e . T h e m a x illa ry is w id e a n d tr u n c
a te d a t its lowe r e n d , a n d n a rrow s g r a d u a lly to its a r tic u la
tin g e x tr em ity . T h e l ip s fo ld b a c k o n th e jaw s , a n d
* T h is p a tch is omitted in tbe figure.