414 EXPLOEATIONS ACROSS THE GREAT BASIN OF UTAH. 



Rafinesqiie (not Lac<^pecle), has been found to be identical with Synechoglanis of Gill. 

 The most essential characteristics of that genus had been omitted by the former natu- 

 ralists who had described its species. The present author, not willing to believe that 

 such was the case, although recognizing the similarity of external appeai-ance between 

 the type of Synechoglanis and the Pimelodus coerulescens, described it under the new 

 generic name. When an opportunity was at length offered to examine species of the 

 group typified by Pimelodus ccendescens, its generic identity with Si/necJwglanis was 

 evident. We have, therefore, renounced our own name, under which the genus was 

 first truly characterized, and adopt the prior designation of Rafinesque, but, instead 

 of Ellio2)s, take the name Idalurus, as previously mentioned. 



This second section of Rafinesque's Idnluri was named Leptops, and is charac- 

 terized by the "tail bilobed. Eyes round and very small. Nine abdominal rays 

 Vent posterior. Adipose fins large." 



In this section, two nominal species were included, the Pimelodus viscosm of Ra 

 finesque and his Pimelodus nehidosus. The latter was "said to be totally different fi-om 

 the foregoing, and might jjerhaps form a peculiar section or even subgenus {Opladelus), 

 by the conical head, membranaceous operculum, but particularly, because the first 

 rays of all the fins, except the caudal and adipose, is a kind of soft obtuse spine con- 

 cealed under the fleshy cover of the fins.'' 



Rafinesque's assertion that his Pimelodus nehidosus was "totally different" from 

 the Pimelodus viscosus has neither been substantiated by his own description, nor by 

 the observations and explorations of Dr. Kirtland in the same waters as those in which 

 Rafinesque himself pursued his investigations. The Pimelodus nehidosus and viscosus 

 were doubtless varieties of the same species. The descriptions are mutually ap- 

 plicable to each other, except in those cases where the characters given are evidently 

 fictitious or erroiieous, which, indeed, are very frequent. 



Rafinesque's fourth section is founded on a species, which, according to Dr. Kirt- 

 land, is the adult of the Pimelodus viscosus of Rafinesque. The section is characterized 

 as having the "Tail entire, eyes elliptical. Nine abdominal rays. Dorsal fins sub- 

 medial. Pectoral fins with one flat spine serrated outwards and nine rays. Lower 

 jaw longer." 



The only species of this section was named Pimelodus limosus. The section in 

 question was designated by the name Ilictis. The name, however, should have been 

 spelled Ili/icMhys, in accordance with its thymology and the rule observable for the 

 composition of names. 



Rafinesque has named "a genus" P?/^^'^^'*^^^'^) which appears to have been also founded 

 on the same fish that had already been tlu-ee times indicated in his work. The ficti- 

 tious genus and sjiecies were established only on the evidence of a drawing by Mr. 

 Audubon, of a fish "found in the lower parts of the Ohio and in the Mississippi". That 

 drawing, according to Rafinesque, represented a rayed fin instead of the usual adipose 

 dorsal. Such a feature would be in opposition to that general plan on which naked 

 Silm-oids with two dorsals are constructed,* and it is therefore certain that Audubon 



* The genus Phractoceplmlm of Agassiz forms no exception to this. A mistake similar to that made by Audubon 

 or Rafinesque occurs in the great work on Brazilian Fishes of Spix and Agassiz. A species is figured in the plates under 



