1894.] "»' [Cope. 



to base of anal, 63 mm. ; length to base of ventral (oblique), on 45 mm. ; 

 length of head. 23 mm. 



This species is allied to the T. maculattis Linn., but that species has a 

 larger eye (one-third head) and a longer anal fin (33-3 rays). * 



The number of rays is so constant in numerous specimens, that, if 

 Steindachner's figures are correct, which there is no reason to doubt, tliis 

 form must be distinct. The T. maculatus is ascribed by both Boulenger 

 and Von Jhringto Rio Grande do Sal. 



The proximal part of the maxillary bone is minutely serrate, but not 

 dentate. 



Fifteen specimens. 



Tetragonoptekus eigenmanniokum sp. nov. 



A species of rhombic form, differing from those above described in the 

 smaller number of anal radii, and fewer scales of the lateral line. Depth 

 entering length without caudal fin two and a half times ; length of head in 

 the same 3.4 times. Eye large, longer than muzzle, entering head three 



7 



times, and equal interorbital width. Scales l!2". Radii, D. 11 ; A. 23. 



. "IT 

 Ventral commencing a little anterior to first dorsal ray, not reaching 

 anal. Pectoral reaching ventral. Profile of head very slightly concave. 

 Dorsal and ventral profiles subsequently arched. Color silvery, with a 

 whiter silvery lateral band. No humeral nor distinct caudal spot. Middle 

 caudal rays dusky. 



Total length, 67 mm. ; length to base of caudal fin, 53 mm. ; length to 

 base of anal, 35 mm. ; length to base of ventral (oblique), 26 mm. ; 

 length of head, 15 mm. 



But one specimen presents exactly the typical characters of this spe- 

 cies, but five others probably belong to it. They have a few more scales 

 of the lateral line, as 33-4, and one has 36. They have a basal caudal 

 spot, and four of them show traces of the humeral spot, and have a steel- 

 blue reflection, as in the 1\ jacuhiensia. The small number of the anal 

 rays, 23-4, distinguishes it from the latter, where there are always 27-8 ; 

 and the form is more elongate. 



This species is dedicated to Prof, and Mrs. C H. Eigenmann of the 

 University of Indiana, whose work on the fishes of Suuth America has so 

 elucidated the subject. 



Tetragonopterus laticeps sp. nov. 



Form, elongate oval ; depth entering length (without caudal fin) 2.6 

 times ; length of head into same, 3.75-4 times. Profile of back descend- 

 ing regularly from dorsal fin ; of front, slraiglit or slightly concave. 

 Diameter of eye greater than length of muzzle, entering 3 to 3.3 times in 

 length of head. Front slightly convex transversely, wider than diame- 



* Teste Steindachner, I. c, p. 10. 

 PIIOC. AMER. PUILOS. SOC. XXXIII. 144. L. PIUNTKD MARCH 3, 1894. 



