504 PROCEEDINGS OF THE ACADEMY OF [Jl^^lj, 



the fins light with dark spots. Head 4-4*; D. 1,11; A. 5; Lat. 1., 

 29-30. 



29. Pterygophlichthys juvens sp. nov. Maimingue. 



Type No. 9,876, one specimen (No. 92). 4 cm. Caught with seine 

 at Asuncion, Rio Paraguay, April, 1900. 



Form slender, depth under dorsal H in width. Caudal peduncle 

 compressed. 



Head moderately elevated, its length slightly greater than its width. 

 Two occipital ridges. Nuchal plates rudimentar}-. Occipital pro- 

 cess broad and triangular. Preopercle erectile ; 8-12 teeth on each side 

 in each jaw. 



Eye 2^ in snout, 2 in interorbital, 4 in head. 



Snout and suborbital regions naked. Under side of head, breast 

 and bell}' naked. Dorsal and lateral scutes carinate. 



Base of dorsal equals distance from dorsal to base of caudal. Dis- 

 tance of dorsal spine from tip of snout contained in the length 2^ 

 times. No adipose. Caudal obliciue, not emarginate. j of total length. 

 Height of anal Ih in head. Ventrals ecpial in length to head, reaching 

 base of anal. Pectoral spine reaching l^ase of ventrals. 



Color uniform black, except breast and belly which are silvery. 

 All the fins with alternating light and dark crossbars. Dorsal with 

 6 horizontal bands alternately transparent and black, the base trans- 

 parent, the top black. Anal with four similar bars similarly arranged. 

 Caudal with 7-9 alternating bars, the light ones less distinct. 



Lateral plates 27; head Sf; D. I, 12. 



This species may be the young form of the three adult specimens 

 (PterygopMichthys anisitsi) caught at Asuncion; but no trace of 

 adipose dorsal could be detected. 



30. Ancistrus cirrhosus dubius Eigenm. and Eigenm. 



One specimen. 55 mm. The specimen is so badly mutilated that 

 the identification is doubtful. 



31. Callichthys callichtliys haemaphractus (Hensel). 



One specimen (No. 265), young. 5 cm. Campo Grande. 



32. Haplosternum pectoralis (Boulenger). 



Four specimens (No. 101). 7-9 cm. Rio Branco, Matto Grosso. 



33. Haplosternum littorale (Hancock). 



Two specimens (Nos. 23 and 24). 18 and 19 cm. Arroyo Caruml^ey 

 and Yajamar, Estancia La Armonia. 



These specimens fit the description of littorale in the ''Nematognathi 

 of South America" by E. and E. Two other specimens (No. 155) 



