SOUTH AMERICAN NEMATOGNATHI. 349 



290. Ars^es longifilis. 



Jr;/r.s> lonij/U'li-'' Steiudachuer, Fhissfische Stidam. iv, 19, pi. v, fig. 



3-36, 1882 (Kio Hnambo). 

 Habitat: Kio Huambo. 



291. Arges peruanus. 



Arges peruanu>i Steindacliner, Ichthyol. Beitr. xiv, 51, pi. ix, figs. ,S-6 

 (Amable Maria); id. Flussfische Stidam. i, 23, 1879 (Ainable Ma- 

 ria; Tambillo; Chota). 



Habitat: Andes of Peru. 



LXIX. Cyclopium. 



Pimelodu.s Humboldt, Obs. Zool. i, 21, pi. 6, 18. (sp.) 



Arges Cuv. & Val. xv, 340, 1840. (sp.) 



=zGjjclo2nu'm Swaiiisoii, Nat. Hist. Fish, ii, 305, 1839 

 {humbol(.ltii= cyclopurn) . 



^Stygogenes Giinther, Cat. Fish. Brit. Mus. v, 223 

 (hiimboldtii). 



Type: Pimelodus cyclopwin Humboldt. 



Adipose fin short, placed near the caudal, with a short 

 spine. Teeth small, those of the mandibles and the inner 

 ones of the intermaxillary broadened and notched at the 

 tip. Eyes small, placed on the upper surface of the head. 



If the species Pinieloilas cydopiiin is ever to be recog- 

 nized it must be referred to the genus Stygogenes Giinther 

 ^=:zCydopium Swainson. The poor description of P. cyclo- 

 purn makes an absolute identification impossible. There 

 are, however, in the Museum of Comparative Zoology, 

 tw^o specimens from Quito — i. e. from the habitat of P. 

 cyclopurn — which fairly agree with the figure and de- 

 scription of P. cyclopiim, leaving out of consideration 

 the spine in the adipose fin. They also agree w^ith the 

 description of Stygogenes hiundoldtii Gthr. with the ex- 

 ception of the number of fin rays. The two species may 

 be considered identical. Putnam (Am. Nat. 1871) 

 identifies with it also Arges hi'achycephaliis, but a re-exam- 

 ination of the types of the two forms by Dr. Giinther 

 proves them to be distinct. 



