﻿REVISION OF GENUS HARENGULA — RIVAS 279 



to separate the slender from the deeper forms. The greatest width 

 of the head, the distance between the origin of the dorsal fin and the 

 axis of the body, and the least depth of the caudal peduncle, all into 

 the head, have been found to be valuable characters. In general, 

 deep-bodied forms have a shorter head and a smaller eye. 



The general coloration is practically the same in all the American 

 forms and varies only in minor details. //. humeralis and H. callolepis 

 are the only species without the humeral spot. These two species 

 and H. thrissina have the tip of the dorsal fin blackish, whereas in the 

 remaining species it is shghtly or not at all pigmented. 



The American species and subspecies of Harengula are closely related 

 and sometimes difficult to separate. They overlap in virtually all 

 counts and proportions, although there is a combination of characters 

 for each form that serves to separate it from the others. The following 

 key, arranged dichotomously, should provide a ready means of 

 identification for them: 



KEY TO THE AMERICAN SPECIES AND SUBSPECIES OF HARENGULA 



la. Inner edge of palatines with a row of pointed teeth forming a cutting edge; 



gill rakers less numerous, 26 to 32, usually 27 to 31, on lower limb of first 



arch; ventral scutes less numerous, 25 to 29, usually 26 to 28; scales not 



adherent, easily falling off from either fresh or preserved specimens; distance 



between origins of pelvic and anal fins shorter 3.7 to 5.0, usually 3.8 to 4.5, 



in length; snout longer, 2.5 to 3.4, usually 2.6 to 3.3, in distance between 



origins of pelvic and anal fins; humeral spot absent; average length 82 to 



140 mm. 



2a. Gill rakers less numerous, 26 to 31, usually 27 to 29, on lower limb of first 



arch (see table 1); head deeper, its depth at occiput 3.7 to 4.0, usually 



3.8 or 3.9, in length; distance between occiput and origin of dorsal fin 1.4 



to 1.6, usually 1.5, in greatest depth of body; body deeper, its greatest 



depth 2.9 to 3.3, usually 3.0 to 3.2, in length; eye larger, 1.7 to 2.2, usually 



1.8 to 2.1, in distance between occiput and origin of dorsal fin; average 



length 82 to 106 mm.; Florida Keys, Bahamas, West Indies, and Atlantic 



coast of Central and South America from Yucatdn to Venezuela. 



1. Harengula humeralis 



26. Gill rakers more numerous, 29 to 32, usually 30 or 31, on lower limb of first 



arch (see table 1); head less deep, its depth at occiput 4.1 to 4.4, usually 



4.2 or 4.3, in length; distance between occiput and origin of dorsal fin 



1.1 to 1.3, usually 1.2, in greatest depth of body; body less deep, its 



greatest depth 3.3 to 3.9, usually 3.4 to 3.8, in length; eye smaller, 2.1 to 



2.7, usually 2.2 to 2.6, in distance between occiput and origin of dorsal 



fin; average length 109 to 140 mm.; Bermudas.. 2. Harengula callolepis 



\h. Inner edge of palatines without a row of pointed teeth; gill rakers more 



numerous, 28 to 40, usually 30 to 39, on lower limb of first arch; ventral 



scutes more numerous, 28 to 32; scales adherent, not falling off from either 



fresh or preserved specimens; distance between origins of pelvic and anal 



fins longer, 3.1 to 3.9, usually 3.3 to 3.7, in length; snout shorter, 3.4 to 4.3, 



usually 3.5 to 4.2, in distance between origins of pelvic and anal fins; 



humeral spot present, sometimes faint; average length 42 to 91 mm. 



