THE GYMNOTID EELS OP TROPICAL AMERICA. 125 



The following is extracted from Steindachner's original account. 



"Snout 3 in the head; eye 7.5 to 10.5 in the head, 2 to almost 4 in the snout, 

 depth of the head about 1.4 (more than 1.3) in the length of the head; head 9.5 

 to 11 in total length. 



"Eye with a free lid, its diameter in young individuals twice the interocular 

 distance, in old specimens about three times the interocular. 



"Anal begins slightly in front of the vertical from the base of the pectoral and 

 contains more than three hundred rays. 



"The head of this species is noticeably deeper, the snout shorter in profile and 

 more strongly arched than in Sternopygus carapo = {Sternopygus macrurus)." 



It seems quite probable that this species may be but a variety of Sternopygus 

 macrurus. 



Distribution: Middle Amazons and Rio Madeira; north coast of Brazil. 



IV. EiGENMANNiA Jordan and Evermann. 



Sternopygus Muller and Troschel, Horse Ichthyol., Ill, 13 (Species). 



Cryptops Eigenmann, Ann. N. Y. Acad. Sci., VII, 626 {huniboldtii) . (Preoccupied.) 



Eigenmannia Jordan and Evermann, Fishes North and Mid. Amer., I, 341, 1896 



(Substituted for Cryptops). 



Type, Sternopygus huniboldtii Steindachner. 



Distinguished from Sternopygus by the absence of a free orbital margin. 

 With fontanels; no caudal; snout short. Size moderate, not exceeding 400 mm. in 

 length; body elongate and compressed; maximum depth and thiclmess in the 

 region of the pectorals; head moderate to small, and rather short; gape small, 

 curved downward and back; jaws equal, the lower included on the sides; teeth in 

 two lateral patches in the lower jaw and two almost confluent median patches in 

 upper jaw; mouth rather small; eyes medium, covered by a transparent membrane. 

 Scales cj'cloid; lateral line complete. Origin of anal back of the vertical from the 

 origin of the pectorals; caudal appendage moderate to quite long. 



Fig. 4. Eigenmannia virescens (Valenciennes). 



