172 Mr. G. A. Boulenger on new 



the carapace and plastron. Plastron formed of the normal 

 nine bones *, without persisting fontanelles. 



XXIII. — Descriptions of neio South- American Characinoid 

 Fishes. By G. A. Boulenger. 



Curimatus hypostoma. 



D. 11 (1. 10). A. 9 (I. 8). V. 9. L. lat. 49-52. 

 L. transv. g. 



The height of the body equals or slightly exceeds the 

 length of the head, and is contained four times in the total 

 length (without caudal). Abdomen flattened in front of and 

 behind the ventrals. Snout as long as the diameter of the 

 eye, strongly projecting beyond the mouth, flattened interiorly ; 

 the diameter of the eye is contained thrice and one third to 

 thrice and two thirds in the length of the head ; a much 

 developed adipose eyelid in front and behind. Caudal fin 

 deeply forked, a little longer than the head. The height of 

 the dorsal is a little less than the length of the head; its 

 origin is midway between the end of the snout and the adi- 

 pose fin, corresponding to the tenth to twelfth scale of the 

 lateral line. Extremity of pectorals separated from base of 

 ventrals by a length of three or four scales ; ventrals not 

 reaching the vent. Scales with their entire margin con- 

 spicuously serrated. Uniform silvery, back darker and with 

 bluish reflections ; lower caudal rays darker. 



Total length 120 raillim. 



Four specimens ; from the Ucayali River, collected by 

 Mr. W. Davis ; presented by Messrs. Veitch. 



Allied to C. asper, Gthr., and C. trachystethus, Cope; but 

 the body is much less elevated in this species, which even 

 surpasses G. albula, Gthr., in the strongly projecting snout. 



Tetragonopterus Iheringii. 

 D. 2/8. A. 3/16-18. L. lat. 35-37. L. transv. ~l. 



Lateral line complete. The greatest depth of the body is 

 contained twice and two thirds to thrice in the total length 



* I think it may be talcen for granted tliat there are no intersternals, 

 and that the triangular shield represented on pi. iii. is merely part of the 

 marginal, the plastron having been sawed off. 



