risii.
crenatmes. Lateral line Interrupted ; its first portion at the depth of two and a h alf rows o
seales beneath the dorsal, and stopping beneath the commencement of the soft p art of that hn ;
recommencing three rows lower down, exactly in the middle of the depth, whence it runs
straiMit to the caudal. i • i, q
Dorsal commencing above the opercle; the spinous portion of nearly uniform height, and
scarcely more than one-fifth of the d ep th ; the soft portion much higher, and term inating m a
sharp point behind. Anal answering to the posterior half of the dorsal, term inating opposfie to
it, and similarly p ointed; with six spines, which, as well as the dorsal spines, are fam ished
with very eonspieuons filamentous tags. C audal nearly even. Pectorals rounded, h u t not
very broad, their length rather more than three-fourths that of the head ; the rays rather slender
V entrals p ointed ; the first soft ray elongated, and reaching to the anal when laid back ;
the last ray attached at its base by a membrane to the abdomen. Hows of small soaks between
the rays of the caudal at the base of the fin ; and a few small ones along the base of the dorsal
and anal, more particularly on the soft portions. _
C o l o u r . - « Above, greenish black ; the sides paler ; slightly irideseent.”- D . - I n spirits it appears
of a nearly uniform brown all over, fins included.
H abitat, Maldonado, Rio Plata.
Mr Darwin obtained this species at Maldonado, in a lake ot fresh water, said
sometimes to be a little brackish. It appears to belong to the genus Chrmms of
Cuvier placed by him amongst the Labvidai, but having evidently very strong
affiniti/s to some of the Scicenidce. It differs essentially from the C. Brasihensie
of Quoy and Gaimard,* in having six anal spines, and being destitute ot all
markings and spots. I am not aware that it is described hy any author.
1. S c a r u s c h l o r o d o n . J e n .
P l a t e X X L
V. m-ngincso cjancus, capite et pinnis flavo-vittatis: maxillis exterih Iceuibus, mar-
ginihus crenatis; caninis ad angidos oris nullis: fronte gradahm proclivi: linea
laterali tuhis parum ramosis : squamis ubique striato-granulatis : pectoralibus acuminatis,
radiis superioribus arcuatis; caudali radiis externis ceteris longioribus,
acuminatis.
D. 9 /1 0 ; A. 3/9 ; C. 13. & c .; P . ISvel 16 ; V. 1/5.
L o n g . u n c . 16.
PORVI - O f an oval form ; the greatest depth one-third of the length, caudal excluded; dorsal and
ventral lines equally convex. H ead a little less than the depth o f the body, not gibbons m
front, but with the profile falling regularly and gradually from the eommeiicement of the dorsal.
Snout rather pointed. Jaw s equal, their outer surface smooth, but crenated on their cutting
edges. N o spinous canines at the com ers of the month. Eyes rather small, their diameter not
o n tfifth the length of the head, situate above the middle of the cheek, but eqn .d^tan t from the
posterior lobe of the opercle and the extrem ity of the snont. Snout in front of the eyes, and
• Freycinet Voyage, (Zoologie) p. 286.