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 con-espond 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; broAvn 

 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. 



