Evermann and Kendall Fish from Central Ecuador. 99 



fissidens have but little left by which to distinguish them and 

 the same may be said of sabalo, taczanowskii, vaillanti and 

 prenadilla. 



Since the male examples of our specimens agree with all that 

 has been said of Arges prenadilla, and the females equally as 

 well with Cydopium cydopum, we are forced to unite these two 

 forms in the genus and species Cydopium cydopum, which will 

 include A. eigenmanni and perhaps whymperi of Regan. There 

 is nothing in the laws of nature, so far as we know, to prevent 

 the existence of a number of genera and species of this group of 

 fishes ; but the indications derivable from the literature and 

 material at hand are that the number may be still further 

 reduced as a result of more extended investigations, and there 

 may be but one genus, Astroblepus, to include all the nominal 

 species. 



The following description of Cydo^num cydopum is based on 

 two individuals, female and male, each about 3.12 inches in 

 length, in the collection sent us by Dr. Davis: 



FIGS. 1 and la. --Cydopium cydopum, female. 



Female. Head 4.18 in length to base of caudal ; D. 7 ; A. 7 ; RIO; V. 5 ; 

 C. 13. Body rather robust, somewhat depressed anteriorly and compressed 

 posteriorly; a thick fleshy fold or ridge (after months in alcohol), some 

 what arched, extending from a short distance back of dorsal to base of 

 upper ray of caudal, with a small rough, nearly concealed, spine 

 posteriorly ; skin rather loose and wrinkled, full of fine mucous pores 

 posteriorly to dorsal, coarser in front; first dorsal, outer pectoral and 



