50 FISHES FROM BRAZIL 



170. Sagenichthys ancylodon (Bloch and Schneider). 



Sagenichthys viordax Gilbert and Starks (Mem. Cal. Acad. Sci. IV., 

 1904). 



Three specimens from 7 to 8 inches in length were collected at Para, 

 which enable me to compare directly, for the first time, this species with 

 Sagenichthys mordax from the Pacific. 



When Sagenichthys mordax was described it was compared with cur- 

 rent descriptions of S. ancylodon and from these it appeared to differ in 

 having larger scales in the lateral line, smaller scales on the rest of the 

 body, and shorter gill-rakers. All of these characters have been inaccu- 

 rately described for S. ancylodon and a direct comparison of the specimens 

 from both coasts fails to "show any specific differences. There are about 

 100 oblique series of scales above the lateral line in S. ancylodon (not 85) 

 and half as many scales on the lateral line (not 75). The gill-rakers are 

 one-third of the diameter of the eye (not two-thirds). The specimens from 

 Para have a somewhat larger eye than those from Panama, but the difference 

 is not too great to be accounted for by the difference in size of the specimens. 



171. Nebris microps Cuvier and Valenciennes. 



Four large specimens of this species were taken at Para, each of them 

 a little over a foot in length. This makes a direct comparison between this 

 species and its representative in the Pacific, Nebris occidentalis Vaillant, for 

 the first time possible. 



Comparing them with some specimens from Panama of similar size the 

 mandible is strikingly weaker and does not protrude nearly so much, lacking 

 the large, sharp process at the symphysis. The lips are thinner and the 

 mouth is less oblique. There are 95 series of scales above the lateral line, 

 counting the nearly vertical series, and 11 scales between the lateral line and 

 the front of the soft dorsal. These counts in Nebris occidentalis are respec- 

 tively 115 and 20. The scales on the belly are very much larger in Nebris 

 microps. The pectoral is shorter, or ly^ in the head, while in the other 

 species it is almost equal to the head. The radiating striations on the pre- 

 opercle are not nearly so coarse and do not end in such coarse pectinate 

 processes. The body is marked with 6 or 7 wide, conspicuous, dark cross 

 bars, which are not evident in Nebris occidentalis and have not been described. 



The following is the color of fresh specimens. The back is dusky drab, 

 with wide, nearly black, cross bars, anteriorly not so wide as the interspaces, 

 posteriorly more crowded and equal to them. There is a trace of one over 

 the opercle, one under the spinous dorsal, four under the soft dorsal, the first 



