﻿396 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loo 



Diagnosis. — A Dorosoma with 46 to 48 vertebrae, 70 to 82 lateral 

 scales, 46 to 54 scales around the body, 10 to 13 (most frequently 11) 

 dorsal rays, 29 to 38 anal rays, usually 18+10 or 18+11 ventral 

 scutes, and with a long dorsal filament. 



Relationships. — D. anale differs from cepedianum principally in 

 having smaller scales and fewer vertebrae (tables 3 and 4) and in the 

 ratio of the length of the anal fin base to the distance between the 

 pelvic insertion and the tip of the snout. This ratio varied from 1.1 

 to 1.4 (usually 1.2-1.3) in 23 specimens of anale 83 to 256 mm. long, 

 and from 1.4 to 1.9 (usually 1.6-1.7) in 24 specimens of cepedianum 

 84 to 250 mm. long. It is sharply distinguished from both smithi and 

 chavesi by the longer anal base and by the greater number of anal 

 rays, the much longer dorsal filament, and the more anterior pelvics 

 (tables 2 and 5) . Its close relationship v/ith cepedianum is indicated 

 by the long dorsal filament, the high number of anal rays (25 to 36 in 

 cepedianum), the similar number of prepelvic scutes (predominantly 

 18 in both), and the anterior position of the pelvics. It resembles 

 both of the southern species in the fine scales and in the number 

 of postpelvic scutes (tables 3 and 4). 



Variation.- — Counts of fin rays, scales, and ventral scutes were 

 recorded for 21 to 71 specimens from Veracruz and Tabasco, Mexico, 

 and from Peten, Guatemala (tables 2-4). In addition, 24 measure- 

 ments were made on each of 35 specimens (table 6). With the excep- 

 tion of the number of vertebrae, the meristic characters and the pro- 

 portional measurements of this material were rather consistent. The 

 southernmost stocks from Peten, Guatem.ala, yielded a lower verte- 

 bral number: 46 in 8 specimens, 47 in 2 specimens, and 48 in 1 speci- 

 men, rather than 47 (in 6) or 48 (in 5) for the 11 specimens from the 

 basin of the Rio Papaloapan, Mexico, which were examined for this 

 character. This decrease in number southward is in line with the 

 gradient noted for vertebral number in the species of Dorosoma. 



The caudal rays of 26 specimens were 19 except for a single 18. The 

 pelvic rays of 27 were 8-8 except for one 7-8. 



Material examined. — In the following collections, all from the basin 

 of the Rio Papaloapan in Veracruz, Mexico, all but C.N.H.M. No. 

 3787 and C.N.H.M. Nos. 14621-28, were collected by Meek and are 

 types. These two lots were taken later by Heller and Barbour: 



C.N.H.M. No. 3787: 2 specimens, 67 and 133 mm. long, from Achotal. 



C.N.H.M. No. 4681: 7 paratypes, 52 to 171 mm. long, from P6rez. 



C.N.H.M. No. 4606: 2 paratypes, 98 and 131 mm. long, from Veracruz. 



C.N.H.M. No. 4637: holotype, 145 mm. long, from El Hule (now renamed 

 Papaloapan) . 



C. N. H. M. No. 4708: 2 paratypes, 187 and 188 mm. long, from San Juan 

 Evangelista. 



C.N.H.M. Nos. 14621-28: 8 specimens, 83 to 149 mm. long, from Achotal. 



