EIGENMANN: THE PYGIDIID.E, A FAMILY OF SOUTH AMERICAN CATFISHES. 345 



Head 8; depth 6; D. 10, of which eight arc full length; A. 7, of which five are 

 full length; eye minute, about thirteen times in the head; center of head a full 

 orbital diameter behind the posterior margin of the eye; interorbital 2.1 in the 

 length of the head, snout 3 in the head, broad; width of head equal to its length; 

 maxillary barbel not reaching to the interopercular spines; lower barbel reaching a 

 little beyond the middle of the maxillary barbel; depth of caudal peduncle two and 

 one-fourth in its length ; pectoral about equal to the length of the head without the 

 opercle; distance between origin of dorsal and base of caudal twice its distance from 

 the snout; last dorsal ray slightly in front of the anal; dorsal and anal truncate or 

 slightly emarginate; anus under middle of dorsal; ventrals not reaching anus, their 

 origin equidistant from tip of caudal and interopercle ; caudal deeply forked, the 

 upper lobe two and one-half times as long as the middle rays; caudal fulcra not 

 conspicuous. 



Genus VII. Henonemus 32 Eigenmann & Ward. (Plate XXXVI). 

 Henonemus Eigenmann & Ward, Ann. Carnegie Mus., IV, 1907, p. 118 {inter- 

 medins) . 

 Cobitiglanis Fowler, Proc. Acad. Nat. Sci. Phila., 1914, p. 268, fig. 16 (taxistigma) . 

 Type. — Stegophilus intermedins Eigenmann & Eigenmann. 

 The genus Henonemus was created for Stegophilus intermedins on the obser- 

 vation that it has but one barbel at the angle of the mouth. The second (lower) 

 barbel at the angle of the mouth is so minute that it ought not to be considered of 

 generic value, especially since a minute barbel has been found on closer observation 

 in a number of cases where but one barbel had been recorded. It is probably present 

 in the type of Henonemus. The types of Homodicetus and Henonemus differ in the 

 number of opercular spines, four or five in the former, but two in the latter. The 

 names may, therefore, be at least temporarily retained. 



Cobitiglanis was proposed as a subgenus of Ochmacanthus. However, the type 

 of Cobitiglanis is not related to Ochmacanthus. Cobitiglanis taxistigma is scarcely 

 distinct from H. punctatus and the name Coblitiganis is a synonym of the subgenus 

 Henonemus. 



This genus, as far as known, consists of free-living species, and is closely re- 

 lated to the commensal Stegophilus. The mouth is wide, inferior, provided with 

 numerous teeth in series on the jaws and lips; those of the middle of the upper lip 

 are long and in part are homologous with those of Vandellia; the opercle bears two 

 spines, the pre-opercle five or more. Where observed, the lower barbel is very 

 minute, followed by an additional barbel or labial lobe; the lower jaw is well formed, 

 32 1„ = one, vma = thread. A misnomer, since there are two maxillary barbels. 



