194 
MONTAGU'S SUCKER. 
is more stout and fat than that which is nearer the tail, and 
the rays more separated and not so high, the appearance is as 
if there were two dorsal fins. 
The females, as far as they have been seen, are larger than 
the males, and the longest of them measured three inches. 
The head broad, flat on the top, cheeks tumid; the front 
descending from above the gill-covers; snout rounded and pro- 
truding; under jaw beneath, a rough bed of teeth in each; 
mucous orifices large round the mouth. Eyes lateral; the body 
round, forward, compressed posteriorly; the skin smooth. The 
dorsal fin begins opposite the half of the pectoral; the anterior 
portion low, and suddenly expanding above the origin of the 
anal fin; behind this both the last-named fins correspond to each 
other, and end near the root of the tail. In examples which 
I consider the male I have found these fins expanded at their 
termination ; but in the females wider at the middle, and narrow 
behind. Tail slightly round, or straight. Pectoral fin has its 
rays longest above, but in a narrower form it unites with the 
ventral to pass under the throat in front of the sucking organ. 
The latter has thirteen protuberances, of which the odd one is 
in front, like the keystone of an arch, The vent is in the 
middle of the body. The general colour is a chesnut brown, 
light on the belly: some examples are much yellower; a row 
of small white dots sometimes runs along the lateral line; brown 
bars on the dorsal and anal fins, and on the tail; with a tinge 
of pink on the border of the pectoral fins and belly. Those 
last-named marks I have only seen on the female. The fin 
rays are, in the dorsal twenty-five, anal twenty; in the pectoral 
twenty-two, and ventral, counted separately, seven. In the tail 
eleven. 
