48 BULLETIN 189, UNITED STATES NATIONAL MUSEUM 



by R. E, Coker. The specimen apparently is an immature male, as 

 the claspers are small and soft, notably shorter than adjacent parts of 

 ventrals. 



The relationship of the several species of Squatina that have been 

 recognized is not well understood. I am not at all certain that the 

 specimen at hand is identical with S. armata (Philippi). I do believe 

 it to be specifically distinct from the specimens from Argentina 

 identified as S. armata by Norman (see citation above), as the Peruvian 

 specimen does not agree with Norman's description of the last-men- 

 tioned specimens in several respects. In the Peruvian specimen the 

 space between the spiracles is narrower than the interorbital space, 

 whereas it is equal to interorbital space in the Argentine specimens; 

 the eye apparently is smaller, being contained in the interorbital 

 space 6.3 times in the Peruvian fish and only 4.5 in the Argentine 

 ones; the caudal fin seems to be more deeply lunate, with the lower 

 lobe more acutely pointed in the Peruvian specimen, which also 

 seems to be rougher underneath, having denticles over a greater part 

 of the ventral surface, on the chest and abdomen (which are described 

 as naked in Argentine specimens) and on virtually the entire under 

 surface of the pectorals and ventrals. All the differences mentioned 

 have been verified from a specimen 510 mm. long (U.S.N.M. No. 

 53440) from Argentina. 



S. californica, the north Pacific representative of the genus on the 

 American coast, differs from the Peruvian specimen, as shown by 

 comparing a female 390 mm. long, taken oft' northern California in 

 having a much narrower nasal lobe on inner side of the nostril, which 

 is not scalloped on its inner base; the internarial space is broader, 

 exceeding the interorbital space; the eye is larger, its longitudinal 

 diameter being nearly equal to the transverse diameter of the spiracle, 

 and is contained only 4.8 times in interorbital space; the distal margin 

 of the pectoral is definitely more concave, and its posterior angle is 

 more sharply rounded ; the denticles on the dorsal surface are notably 

 larger and coarser; and on the ventral surface they are present in a 

 band only along the margins of the pectorals and ventrals, and on the 

 tail, there being none on the bases of the fins and none on chest or 

 abdomen. 



Range. — Probably Peru and Chile. 



Family TORPEDINIDAE: Electric Rays 



Head, trunk, and pectorals forming a subcircular disk; tail short, 

 rather stout, bearing one or two dorsal fins and a caudal fin; with or 

 without lateral dermal folds; electric organs present, situated in 

 shoulder region; eyes and spiracles close together, superior; nasal 

 valves confluent; skin naked, soft and smooth. 



A single genus seems to be represented in the Peruvian fauna. 



