Fishes of the Western North Atlantic 413 



Caudal about 1.5 times length of head, with slender pointed lobes covered with scales 

 anteriorly. 



Color. Body silvery; head yellowish white. 



Size. The largest example reported was 75 mm long. 



Development. Small specimens (40 mm) are more slender than larger ones (75 mm), 

 according to the original description, and the ventral outline is strikingly less convex 

 in the smaller ones. However, the proportionate depth of the caudal peduncle and the 

 greatest depth of the body are about the same in both small and large specimens. 



Range. Known only from Para, Brazil. 



Synonyms and References: 



Clupea amazonka Steindachner, S. B. Akad. Wiss. Wien, 8o, 1879; Ichthyol. Beitr., 8: 65 (orig. descr., type 

 local. "Amazon R. at Para"); von Ihering, Die. Anam. Brasil, 1940: 716 (habitat). 



Rhtnosardinia amazonica Myers (in part not of Steindachner), Copeia, 1929: I {R.serrata thought to be a synon., 

 following Regan, which seems to be incorrect). 



Sardinella {Rhtnosardinia) amazonica von Ihering, Rev. Indust. Anim., i (3), 1930: 229 (synon., diagn., re- 

 lation.). 



Negative Reference: 



Heringia amazonica Regan (not of Steindachner), Ann. Mag. nat. Hist., (8) 29, 1917: 394 (descr. based on 

 cotypes oi R. serrata; synon. apparently incorrect). 



Rhtnosardinia serrata Eigenmann 1912 

 Figures 102, 103 



Study Material. Five cotypes, 60-68 mm TL, 46-49 mm SL, from Morawhanna, 

 British Guiana, USNM 66284. 



Distinctive Characters. See Relationship. 



Description. Proportional dimensions in per cent of standard length, and counts, 

 based on the five cotypes, 46—49 mm SL. 



Body: depth 29.5-32. Pelvic fin: length 1 5.5-1 7. 



Caudal peduncle: depth i. 55-1. 95. Pectoral fin: length 19.2-20.5. 



Head: length 19.5-23.5; depth 20.5- Distance from snout to origin of: dorsal 



21.5. 47-51- 



Snout: length 4.1—4.55. 



Eye: diameter 6.2-6.75. Scales: 35-38. 



Interorbital: width 4.25-4.8. Ventral scutes: 27-29. 



Maxillary: length 9.1 -10. Fin rays: dorsal 14 or 15; anal 15-17; 

 Mandible: length 8.4-9.1. pectoral 11 or 12. 



Anal fin: length of base 12. 7-14. 3. Vertebrae: 29 (105: 394). 



Body rather deep but not excessively compressed, its greatest thickness about a 

 fourth of its depth, its greatest depth 3.1-3.4 in SL; dorsal outline gently convex 



