î'
\ * .
Í î:
f i
I
to th ird segments o f th e postabdomen bave tb e ir po sterio r m a rg in s
dorsally a rmed Avith a scries of m in u te sqñnules ; th e first segment
has a fcAV spinules on tb e p o s te ro -la te ra l m a rg in above th e postero la
te ra l angle ; in th e second segment tb e spinules are more n ume rous,
an d on th e tb ird th ey e x te n d along n e a rly th e Avhole le n g th of th e
p o ste ro -la te ra l marg in s an d along p a r t of tb e in fe ro -la te ra l marg in s
an d (in one specimen) are of ve ry u n eq u a l le n g th ; th e fo u rth segm
e n t is dorsally a rmed on its poste rior m a rg in Avitb ab o u t five
a lte rn a te ly la rg e r an d smaller spinules ; th e re are a feAV m in u te
spinules on th e po sterio r m a rg in of tb e fifth segmen t, an d one a t th e
p o ste ro -la te ra l angles of tb e s ix th segment. ï b e telso n is double,
each of tb e lobes te rm in a tin g in a spinule, above Avbich are several
stiff setæ. The eyes are la rg e , ro u n d , an d black. The supe rior
a n te n næ exceed tb e in fe rio r in le n g th ; tb e an te p e n u ltim a te p ed u n c
u la r jo in t is r a tb e r sh o rte r an d s to u te r th a n tb e n e x t jo in t ; tb e
la s t p ed u n cu la r jo in t n o t lo n g er an d scarcely s to u te r th a n th e first
jo in t of tb e flagellum ; accessory flagellum ab o u t 5-jobited, flagella
imperfect. Tbe a n te p e n u ltim a te jo in t of th e in fe rio r a n ten næ is
ab o u t h a lf th e le n g th of th e n e x t jo in t ; second and tb ird jo in ts sn b -
e q u a l ; flagellum scarcely lo n g e r th a n tb e th ird jo in t. Th e first p a ir
of legs (g n ath o p o d s) a re comparatively slen d e r a n d feeble ; Avrist
an d palm of ab o u t equal le n g th an d th ick n ess, an d p a lm Avitb a
v e ry small an d obscure n o tch in tb e middle of its d is ta l m a rg in ;
d a c ty l ab o u t h a lf as long as palm. Second legs Avith th e h an d s u n eq
u a l ; in^ tb e smaller ( r ig h t) leg th e Avrist is d ila ted d ista lly Avhere
i t is applied to tb e base of th e palm, Avbicb is oblong-oval in form,
Avitb its ve ry oblique d is ta l m a rg in obscurely c ren u la ted an d defined
b y an obscure lobe or to o th ; d a c ty l n o t h a lf as long as palm. The
la rg e r (le ft) leg h a s th e Avrist p o ste rio rly deeply excavated an d
d ista lly enlarged to tb e Avidtb of tb e palm, Avbich is la rg e , massive,
n e a rly oblong in shape, Avith its d ista l m a rg in deeply ex c av a ted , th e
n o tch enclosing a small to o th an d folloAved by a b ro ad tru n c a te d and
d en ticu la ted lobe au d by a spine defining th e p o s te ro -d is ta l angle ;
th e d ac ty l is ab o u t as long as th e d ista l m a rg in o f tb e pa lm, an d
h a s a b lu n t subbasal lobe or to o th on its in n e r m a rg in . Tho th re e
p o s te rio r p a irs of legs have tb e second or b a sus-joints oblong-oval
in shape, an d p o ste rio rly produced a t tb e d is ta l e x trem ity in to a
p rom in e n t to o th or lobe, AA+ich in th o p o ste rio r p a ir is spiniform.
The ram i of th e first th re e p airs of postabdominal appendages are
considerably elongated : th e fo u rth aud fifth p a irs a re hirámose, Avith
tb e ram i subequal, styliform, an d (lik e th e bases) armed Avitb stiff
setæ ; in tb e la s t p a ir th e rami are su b eq u a l an d foliaceous, Avith th e
m a rg in s se rra ted . Colour (in sp irit) reddish, l e n g t h of tb e body
n e a rly 4 lin e s (8 millim.).
Seychelles, 4 -12 fms. ; tAvo specimens.
Botb are somcAvhat mutilated ; the description Avas therefore taken
partly from one, partly from the other specimen.
This species, in tbe form and denticulation of tbe band of tbe
larger leg of tbe second pair, someAvhat resembles tbe Mediterranean
Alcera truncatipes (Spinola) described by Air. Spence Bate* ; but in
th at species^ (and also, it Avould appear, in AI. quadrimanus, Dana,
from tbe Eijis, and in AI. viridis, HasAvell, from tho East-Australian
coast) the bands are similar and the segments of tbe postabdomen
smooth. I t is nearly allied to AI. ramsayi, IlasAvell, referred to in
tbe earlier part of this Eeport, Avhich, boAvever, differs in tbe form
of the hands of tbe second pair of legs (Avhicb bave not tbe deep
notch of AI. diversimanus, and are armed Avitb three nearly equal
teeth), and also in the larger posterior pleopoda, &c.; yet it is
possible that a larger series of specimens would be found to offer
transitional characters serving to unite the two forms. I may noto
here th at there is in the British-Aluseum collection a specimen from
the Corean Seas {Capt. II. C. St. John) which cannot, I think, be
distinguished specifically from AI. truncatipes (Spinola).
* Catalogue of Amphipoda in British Museum, p. 189, pi. xxxiv. fig. 4
(1862).
a :
■ííii' !..
yl7. ]
' :v. i
i d
if I
,1)
I ! '
■I'
I: j
■(