GENUS QUASSILABIA. 105 



Scales large, i)recisel.y as in BLyxostoniay the lateral Hue wejl developed 

 and nearly straight, wijth about 45 scales in its course. 



Air-bladder iu three parts. 



Sexual i)eciiliaiities unknown ; probably little marked. 



But a single species of this genus is known. It is a sort of oflshoot 

 from the genus Myxostoma, but its non-protractile mouth and singular 

 lower lip would seem to indicate some real affinity with ihe genus Ujco- 

 glosKum. 



The name Lagochllus had been previously applied to a genus olOas- 

 teropods by B!auford,and toagenusof Insects by Loew. As Lagochila is 

 substantially the same word, with the same etymology, and as, if written 

 in strict (correctness, it would be Lagochilm also, its authors have seen 

 lit to substitute the name Quassilabia, and thus to forestall all discus- 

 sion as to w^hether the name Laguchila should be retained. As this sub- 

 stitution was made soon after the original description of the genus, and 

 before the name Lagochila' had come into any general use, it is to be 

 hoped that it will be accepted by succeeding ichthyologists. 



Generic Characterizations. 

 Lagochila Jordan & Brayton, 1877. — "Similar to Myxostoma {Ptijchostumus Assmaiz) 

 except in the Btructure of the mouth parts. Dorsal fin short ; lateral lino well fl^vel- 

 oped ; scales large, subequal ; air-bladder iu three paits ; I'outauelle between parietal 

 bones well developed ; pharyngeal bones weak, with numerous small teeth ; upper lip 

 not all protractile, greatly enlarged, but attenuated, and sirgular in form. It consists 

 of two elongated and narrow lobes, separated by a narrow, deep fissure, which extends 

 inward to the edge of the mandible proper, which seems to be armed with a rather 

 hard or almost horny plate, about as iu the genus Pantosteas. The two lobes of the 

 lip are weakly papillose. The lower lip is entirely separated from the upper at the 

 angles by a deep fissure. Over this fissure the skin of the cheek lies as a sort of cloak ; 

 the crease separating this skin from the mouth, extending up on the sides of the muzzle. 

 The fissure between the lips extends dowu on the skin of the under side of the head. 

 The opercle is extiemely short and the eye is entirely lu the posterior part of the head." — 

 (Jordan & Brayton, Proc. Ac. Nat. Sc. Phila. p. 280, 1877.) 



Quassilabia Jordan & Brayton, 1878. — "When the xxixme Larjochila was fiist pro- 

 ])08ed for this genus, its authois were not aware that the mrfsculino form, Lagochilm, 

 had been already given to two different genera, toone of Gastero[>()ds by Blanford aid 

 to one of Insects by Loew. The words Lagochila and Lagochilus are identical in ety- 

 mology and in all except terminations, and many writers would consider them insuffi 

 ciently distinct, and wouhl hold that the name Lagochila should be changed. At 

 present, lam inclined to the contrary opinion ; nevertheless, as the matter stands, and 

 as the name Lagochila lla^ not yet come into general use, less confusion perha|)S will 

 result from renaming the genus, than from any othet course. The name Quanailabia 

 (Jordan &, Brayton) is accordingly suggested as a substitute for Lagochila, considered 

 to be preoccupied in conchology. The etymology is quassus, broken or torn ; labia, lip. 



