G. CUMMATUS. 289 



being three-fourths of that of the head. The ventral extends to, or 

 nearly to, the vent. Silvery, with a yellowish band along the lateral 

 line, terminating in a round deeji-black spot at the base of the 

 caudal. 



The two specimens on which I have founded this species differ 

 most remarkably in the form of the body, although they agree in 

 every other point, so that there can be no doubt that they are of one 

 species. One has the body elevated like a C. Cjiprinokhs, its depth 

 being two-fifths of the total length (without caudal) ; the other has 

 the body oblong, its de])th being contained thrice and a third in the 

 total. Both are of the same length. 



Essequibo. 



a-b. Three and a half inches long. From Mr. Ehrhaixit's CoUcction. 

 2. Curimatus albumus. 



Anodus alburnus, Midi. ^- Trosc/i. Ilor. Ichth. iii. p. 2G. tab. 4. fig. .3. 

 Curiinalus alburnus, Kncr, Denkschr. Acad. Wiss. Wien, 18-jy, xvii. 

 p. 144. 



D. 12. A. 10. V. 10. L. lat. 36. L. transv. 11. 



The height of the body is contained twice and three-fourths in the 

 total length (without caud;d), the length of the head thrice and a 

 half. Orbit with an anterior and posterior eyelid. The belly is 

 romided in front of the ventrals, and scarcely keeled behind them. 

 Caudal fin scaly. The pectoral fins do not extend to the venti'als, 

 which reach to the vent. Immaculate, silvery. 



Lake Amucu (British Guiana) ; Rio Guapore. 



3. Carimatus argenteus. 



Gill, Ann. Lijc. Nat. Hist. New York, 18u8, p. 422. 



D. 10. A. 8. Y. 9. L. lat. 37. L. transv. 13. 



The height of the body is contained thrice and one-third in the 

 total length (with the caudal), the length of the head four times and 

 two-thirds. Snout longer than the diameter of the eye, which is 

 contained once and one-third in the width of the interorbital space. 

 The commencement of the dorsal fin is less than a third of the length 

 of the body nearer to the snout than to the end of the caudal. 

 Silvery : a black spot at the root of tlic caudal fin ; a number of 

 black dots cover the inferior third of the membrane between the 

 middle rays of the dorsal, and give the appearance of a i-ounded spot. 

 {QiV.) 



Trinidad. 



4. Curimatus gilberti. 



Qmii (V (l(dm. Vol/. Umn. Zool. p. 219. pi. -Pi. fig. 1 ; Ci/v. ^- I'al. xxii. 

 p." 10. 



D. 11. A. 9. V. 9. L. lat. 41. 



The height of the body is more than one-third of the total lengtli 

 (without caudal) ; the upper profiI(> is a littl(^ concave above the 



VOL. V. V 



