28 BULLETIN 95^ UNITED STATES NATIONAL MUSEUM. 



Tetragonopterus scabripinnis Cuviek and Valenciennes, Hist. Nat. Poiss., 



vol. 22, 1849, p. 114 ; Rio Rimae, Lima. 

 Tetragonopterus peruvianus GiJNXHEE, Cat. Fish. Brit. Mus., vol. 5, 1864, 



p. 327. — Steindachnek, Herpet.-ichthyol. Ergebnisse einer Reise nach 



Siidamerika, Denkschr. Akad. Wiss. Wien, vol. 72, 1902, p. 55. 

 Tetragonopterus mlcrophthalmus GtJNTHER, Cat. Fish. Brit. Mus., vol. 5, 



1864, p. 324; Peru and Guatemala; part. 

 Astyanaa peruanus Eigenmann, The Fresh-water Fish. Patagonia and 



an Exam. Archiplata-Archhelenis Theory, 1909, p. 266; name only. 



Eight specimens, field No. 09425, 5.3 to 7 cm. in lengtli, from Pacas- 

 mayo ; fifteen, field No. 270, 2.2 to 6.9 cm. in length ; two, field No. 

 269, 9.2, and 9.9 cm. in length; and one, field No. 262, 7.2 cm. in 

 length, from Eimac River below Lima; four specimens, field No. 

 275, 9 to 9.8 cm. in length, from Lima market. 



Head 3.6 to 4 in length ; depth 2.5 to 3 ; eye 3.4 to 4 in head ; 

 snout 3.75 to 4; interocular 2.63 to 2.8; pectorals 1.2 to 1.25; ventrals 

 1.6 to 1.8; D. I, 9 or 10; A. II, 25 or 26; scales 6 or 7-35-6. 



Body rather robust; ventral outline more deeply curved than 

 dorsal outline; snout blunt, nape straight or slightly concave; maxil- 

 lary reaching to vertical from about front of pupil ; eye large ; gill- 

 rakers short and rather slender, 7-|-ll. 



Origin of dorsal midway between tip of snout and bass of caudal ; 

 height of dorsal 1.4 to 1.55 in head; caudal forked; origin of anal 

 under posterior third of dorsal, its anterior rays longest, distal 

 margin concave; pectorals and ventrals vary greatly and the dis- 

 tance between their insertion is variable, varying from 0.76 to 1.14 

 in head. Description based on specimens from the Rimac River 

 below Lima and from the Lima market, 8.9 to 9.8 cm. in length. 



Color in life of field No. 262 from the Rimac River, olivaceous 

 above; silvery on sides and below; iridescent; a gi^eenish silvery 

 lateral band distinguishable posteriorly; anal and sides of belly 

 (laterally) punctate with red; sides of body with olive; median basal 

 part of caudal black; pectoral tinged reddish orange; a large violet 

 spot on opercle; iris dusky with orange in antero-dorsal part. 



Among the larger specimens were ripe females and males. The 

 anal rays in the males are well armed with rows of small sharp 

 spinules, giving them a somewhat thickened appearance; occasional 

 spinules are found near the tips of the longer rays in the females. 

 These specimens in the spawning condition were taken about Novem- 

 ber 6, 1907. 



Specimens from Pacasmayo taken March 12, 1907, also have these 

 spinules. These specimens were not in spawning condition. 



In the Pacasmayo specimens the tips of the pectorals reach to the 

 insertion of the ventrals, and in nearly all of these the ventrals reach 

 to the origin of the anal. The average in individuals from the Rimac 

 is slightly less. 



