80 ECHENEID.E. 



stitiite tliosc close comparisons of individuals, wliicli arc essential to the 

 clear establishment of species. These fishes bear, indeed, to one another a 

 strong general resemblance ; yet I believe that the species will prove nu- 

 merous, and that the two originally mentioned by Linnasus, which have too 

 long appeared to serve for general receptacles, constitute, in fact, the types 

 of two divisions of a genus rich in species. Of seven or eight individuals 

 examined in Madeira, three only could be considered specifically the same. 



A single example only of the fish here figured and described has yet oc- 

 curred ; but it is a species possessing such decided characters, that no scru- 

 ple can be felt in giving it as new. 



Shape generally thin and elongated, yet round and thick forwards at the shoul- 

 ders ; very slender and much attenuated towards the tail. Head, as far back as 

 the shoulders, broad, depressed ; thence the body is nearly round and taper to the 

 root of the caudal fin, where it is subcompressed. The belly is not channelled, but 

 simply rounded. The dorsal and the ventral lines are parallel from the origin of 

 the pectoral or ventral to that of the dorsal or anal fins; behind this point they 

 gradually converge, again diverging slightly at the root of the tail. Thus the 

 depth, from the base of the pectoral to the origin of the dorsal fin, is nearly equal, 

 and between one fourteenth and one fifteenth of the whole length ; but at the 

 hinder end of the dorsal or anal fins, it is only between one third and one fourth 

 as much as at their commencement. The greatest breadth or thickness at the 

 base of the pectoral fins greatly exceeds the depth ; being about one ninth of the 

 whole length : but at the origin of the dorsal or anal fins, it is one eighth less than 

 the depth at the same point ; and at their termination, it is equal to the same. 



The head, seen in profile, tapers forwards from the throat to a sharp thin point ; 

 viewed from above, it is broad and flattened, furnished with an oval sucking-disk, 

 containing twenty-three* transverse laminae, serrated as usual, and extending 

 backwards to about the middle of the pectoral fins. The length of this disk is 

 twice and a half its breadth, and is contained four times and a half In the whole 

 length of the fish. It reaches forward for about a quarter of its length before 

 the eye, nearly to the tip of the upper jaw, which is greatly shorter than the 

 lower, exposing both its broad bands of maxillary brush-like teeth. Palatines and 

 vomer with similar bands of teeth. Tongue scabrous, very thin. Nostrils two 

 minute, oval, simple orifices, close together in a line from tlie eye to the tip of the 

 upper jaw ; the hinder largest. Eye rather large comparatively with some other 

 species ; it is between one seventh and one eighth of the length of the sucker. The 

 outlines of the opercle and preopercle are completely concealed by the skin ; so that, 

 at least whilst recent, or without dissection, the comparative length of the head 

 cannot be ascertained. The cheeks and sides of the head are quite plain, compact, 

 and even. Being unwilling to injure the specimen, I did not count the branchial 

 rays. 



The skin all over appears to the eye finely scabrous or shagreened, but is 

 smooth to the touch. It is not particularly slimy ; but the smell of the fish is very 

 disagreeable, like mucus. 



The lateral line begins high up the shoulder, and is flexuose or wavy at its 

 origin, Ijut straight beyond the pectoral fins, running along tlie middle of eacli side, 

 just within the upper edge of the dark-coloured band, and continuing uj) tlie cau- 



* Not twL'iity-lour, as by a slip of the pen in Suiipl. M;al. Fisiios. 



