ON THE SPECIES OF THE GENUS ANOSTOMUS. 23 



ANOSTOMUS PLAT.ZE, sp. n. 

 D. 12 ; A. 11 ; V. 9 ; L.I. 45 ; L. tr. 



4(5) 



Mouth opening forward, lower jaw a little longer, teeth 

 crenulate in both jaws. Length of snout equal to that of 

 the eye. Depth of body three and one-half, or length of 

 head four and two-thirds times in the total length, with- 

 out the caudal. The ninth ray of the dorsal fin is over 

 the middle of the length. The row of scales from the first 

 ray of the ventral toward the hinder part of the dor- 

 sal leads to the third ray from the end of the latter. 

 There are six rows of scales between the lateral line and 

 the dorsal and four between the line and the first ray of 

 the ventral or five from the line to the median ventral se- 

 ries. This species is stouter in front of the dorsal and 

 more decurved about the occiput than A. isognathus; it 

 has larger scales and a smaller number of rows on the ven- 

 tral region. 



Color silvery, back darker, with .lighter streak on the 

 middle of each scale ; a faint spot at base of caudal. 



Hob. Rosario, La Plata. 



ANOSTOMUS NASUTUS Kn. ; Gth. 



% 



Mouth opening obliquely downward and forward, lower 

 jaw shorter, teeth crenulate in upper and lower. Six series 

 of scales between the lateral line and the dorsal, five between 

 the line and the ventral, and seven between the line and 

 the median row of the belly. From the darker lateral 

 edges of the scales, the body has the appearance of be- 

 ing longitudinally streaked with dark. The caudal spot 

 fades out gradually forward as in A. isognathus. Fifteen 

 specimens from the Rio Puty. 



