1903.] NATURAL SCIENCES OF PHILADELPHIA. 521 



humeral spot just above the origin of the lateral line. The lateral 

 line varies considerably in the degree of completeness. In three speci- 

 mens at least it extends to the caudal, but is interrupted. In the ma- 

 jority it stops far short of the caudal. 

 66. Poecilurichthys scabripinnis (Jenyns). 



One specimen, 32 mm. (part of 219), Arroyo Pypucu. One speci- 

 men (228), Arroyo Chagalalina. 



Scales 7-35-5; D. 11; A. 26-29; head 3f; depth 2f. 

 One tooth on the maxillary; a conspicuous lateral band from eye 

 to the end of the middle caudal rays, diffuse on the head, narrow on the 

 sides in front, darkest and widest on the caudal peduncle. No humeral 

 spot. Back with numerous pigment cells. 



Compressed. Mouth small, maxillary not reaching l^eyond anterior 

 mar2;in of eye. Eye 2h in head, greater than interorlDital, snout 1^. 

 Origin of dorsal behind ventrals, nearer caudal than tip of snout. 

 Anal not falcate. Pectorals about to ventrals, ventrals to anal. 



These specimens differ distinctly from scabripinnis in color, having 

 a conspicuous black band. They were, however, preserved in formalin, 

 which has a tendency to destroy the silvery structural bands and to 

 bring out the underlying black pigmentary markhigs. The species 

 is evidently closely related to icappi from British Guiana. 

 67. Poecilurichthys multiradiatus Steind. Mojarra. 



Ten specimens, 39-93 mm., from Asuncion (14, 70, 93, 137, 38, 168). 

 These specimens differ from the typical multiradiatus of the Amazons 

 in the number of rays and scales. 



Anal 41-45 (40-41 in specimens from Teffe, the type locality). 

 Lat. line 45-47(41-42 in the types). Depth 2-2^ (2). 

 Caudal spot distinct, becoming faint with age; humeral spot indis- 

 tinct or absent. Maxillary toothless, or with a single rather large 

 caducous tooth near its upper end. 



It is possible that these specimens represent a distinct species. 



68. Poecilurichthys ahramis Jenyns. Mojarrita. 



Three specimens, Asuncion (11); Arroyo Trementina (246). 



Humeral spot oval, distinct; A. 30 and 32; scales 10-46-9 and 

 9_44_9. This species is very similar to lacustris. 

 69 Poecilurichthys maculatus lacustris LUtken. Mojarra. 



Twenty-three specimens, Asuncion (88, 84, 12), Estancia La Armonia 

 (16), Arroyo Trementina (181, 251, in part 243). 



Anal 27-31; lat. 1., 37-40. In a number of specimens there is a 

 black spot at the base of each scale of the sides, forming longitudinal 

 stripes. 



