534 PROCEEDINGS OF THE ACADEMY OF [July, 



parts of soft dorsal, anal, and first ventral ray much prolonged. 

 Caudal truncate, 25. Pterophyllum. 



101. .ffiquidens tetramerus Heckel. 



Many specimens from Rio Branco (102); Campo Grande (153); 

 Estancia La Armonia (22); Arroyo Trementina (183, 250); Arroyo 

 Carumbey (20); Tolducuc (232, 233); Salamanca (258). 



D. XV, 10 or 11 ; A. Ill, 8-10; lat. 1., 14-18 + 7-9. 



102. .ffiquidens paraguayensis sp. nov. Pira mbocaya. 



Type No. 10,066, a specimen, 100 mm. (part of 66), Asuncion. 



Co-types No. 10,067, nine specimens (66), Asuncion. 



Co-types No. 10,068, five specimens (169), Laguna Asuncion. 



Co-types No. 10,069, five specimens (190), Asuncion (?). 



Co-types No. 10,070, ten specimens (238), Aquadas. 



Other specimens are No. 10,071 (218), two Arroyo Pypucu; No. 

 10,073 (271), one Asuncion; No. 10,074 (217), four Arroyo Pypucu. 



This species is evidently very closely related to JEquicIens dorsigera 

 (Heckel) and Mquidens syspilus (Cope). Steindachner states that 

 dorsigera is characterized by a black spot on the spinous dorsal, which 

 was present in all the numerous specimens examined by him. None 

 of the specimens of the new species have such a spot. From syspilus,^^ 

 as far as the meager figure and description of Cope permit a comparison, 

 this species differs chiefly in the number of scales and rays. 



Description of the type: 



Dorsal XIV, 9; A. Ill, 7; lat. line 16 + 10 (24 in the series Which 

 carries the posterior segment of the lateral line) . Head 2f ; depth 2|-. 



Elevated in front, head broad, eye above the tip of the snout, pre- 

 orbital equals eye. Eye 3^ in head, 1 in snout, slightly less than inter- 

 orbital. Cheeks with three rows of scales; scales of the body large, 

 of nearly uniform size. The middle rays of the soft dorsal and anal 

 prolonged, reaching beyond middle of caudal, the longest dorsal ray 

 reaching from tip of snout to second fifth of the pectoral. Caudal rays 



'^ Cope's description, Proc. Acad. Sci. Phila., 1871, p. 255, of syspilus from the 

 Ambyiacu is as follows: 



"Scales in three series on the cheeks, on the body 2-26-7. Radii D. XIV-XV, 

 9; A. Ill, 8; caudal rounded. Form elongate oval; depth of body 2.6 times in 

 length without caudal fin, and equal depth of head. Preorbital bone half orbit 

 (in specimen two inclies long) ; orbit 2.5 times, head nearly twice interorbital 

 space (doubtless much smaller in larger specimens). Profile convex; muzzle 

 oblique; upper lip longer than mandible. 



"Light brown, yellow below. A straight wide black band from the upper pos- 

 terior margin of the orbit to below the end of the spinous dorsal, composed of three 

 confluent spots; a black bar from eye to angle of preoperculum, and another 

 across the base of the caudal fin. Seven vertical brown cross shades behind the 

 head, on sides." 



