118 ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 
Genus—MESITES. Jen. 
Corpus elongatum, gracile, antice subcylindricum, postice compressum, nudum, squamis 
nullis. Caput depressum. Rostrum breve, obtusum: os terminale, rictu modico. 
Mawille debiles ; superior margine ex ossibus intermawillaribus omnino formato, 
maaxillaribus retroductis et a labio partum celatis. Dentes minuti, acuti, in maxilla 
utrdque uniseriati ; in lingud et vomere biseriati; in ossibus palatinis et pharyn- 
galibus nulli. Apertura branchialis amplissima, membrand sex-radiata, subter 
gulam profunde emarginatd, haud isthmo annexd. Pinne dorsalis et analis valde 
retroposite, opposite. Pinne pectorales et ventrales parve. Pinna caudalis 
leviter emarginata. 
There can be no doubt, I imagine, as to this being an entirely new form, 
and a very interesting one, from the circumstance of its being at the 
extreme end of the family to which it belongs, and its very much departing from 
the usual characters of that family. I have referred it to the Cyprinide, taking 
that group in the enlarged view in which Cuvier accepts it ; though by those who 
divide it into subfamilies it would probably be associated with the Cobitide, or 
made to constitute a distinct one by itself. It agrees with the Cyprinide in 
general in the form of its mouth, in the upper jaw having its margin entirely 
formed by the intermaxillary, the maxillary being present, but placed behind and 
partly concealed in the thickness of the lip, and in the want of an adipose ; but 
it altogether departs from that family in the entire want of scales, of which there 
is not even a vestige in the dried skin, and in which respect it would seem to 
shew an affinity to the Stluride. Yet it has none of the other characters of the 
family just mentioned. On the other hand, in the backward position of the 
dorsal and anal fins, which are opposite to each other, it agrees with the Esocide. 
The pharyngeal bones are unarmed, but this deficiency is made up for by the 
strong curved teeth on the tongue, independently of the minuter ones in the jaws. 
The intestine is extremely short and quite straight, measuring only fourteen 
lines in length from the pylorus to the anus, in a specimen two inches and a half 
long. The stomach is of an oval form, of considerable capacity, very mem- 
branaceous, with. the cardiac and pyloric openings near together at the upper 
extremity, from the latter of which the intestine is immediately reflexed to pass 
off to the anus. In the specimen dissected, the stomach was much distended by 
a nearly perfect individual of the genus Colymbetes, which appeared to have been 
recently swallowed, and was scarcely at all altered. There are no cecal append- 
ages. The air-bladder is of an elongated oval form, and of considerable de- 
velopment. 
