96 Evermann and Kendall Fish from Central Ecuador. 



includes the group in a subfamily Argiinse in the family Lori- 

 cariidse. 



The following list enumerates the characters which, according 

 to Regan, distinguish the subfamily Argiinse from the other sub 

 families of the Loricariidse, and which, as suggested by Dr. Gill, 

 and according to our own view, are sufficient to establish a well 

 marked family : 



Teeth in jaws in more than one series ; no pseudobranchise ; 

 body naked, no bony plates or scutes ; rudimentary ray of 

 ventral present, represented by a small internal round plate ; 

 stronger ribs ; neural and haemal spines somewhat less expanded ; 

 pterygoid small, instead of large and not connected with the 

 prefrontal ; clavicle and coracoids running somewhat forward 

 to their symphyses instead of the lower portions lying trans 

 versely between the bases of the pectorals. 



In this subfamily, as he regards it, Regan recognizes only one 

 genus, Arges, substituting Cuvier & Valenciennes 's name for 

 Swainson's Cydopium for the following reason which he gives 

 in a footnote on page 307 (1. c.) : 



Swainson established the genus in these words: "The third genus is 

 that by which we distinguish the PimeJodus cyclopum of Humboldt (Cydo 

 pium humboldtii Sw.)." His generic name being derived from the genitive 

 plural of Cyclops, is as inadmissible as would be that of Silurorum. 



While most American zoologists regard as very objectionable 

 the use in generic nomenclature of the genitive plural form of 

 a substantive, they do not hesitate to accept such words when 

 once used, retaining the original spelling. Any other practice 

 tends away from stability of nomenclature. But whatever view 

 one may hold regarding this matter, Mr. Regan's contention 

 does not hold in the case under consideration. Cydopium is 

 not the genitive plural of Cyclops, as he imagines, but the neuter 

 form of the adjective cydopius. 



The only character that separates the genera Arges and Cydo 

 pium is the presence of a spine in the location of the ' ' adipose 

 fin " of the latter. That this spine may have been easily over 

 looked in other specimens, since it is so often concealed under 

 the skin in ours, is evident. By an examination of specimens 

 of the species of Arges, it is possible that a spine may be found. 

 This character is therefore of doubtful value. 



Regarding Astroblepus, it remains to be said that, for the same 



