18 EEPOET OF COMMISSIONER OF FISH AND FISHEEIES. 



work. The species is not well separated, and is at best but a geographi- 

 cal race of Brevoortia tyrannus. 



Darwin'' s Menhaden. 



37. The Alosa pectinata described by Jenyns,* from specimens col- 

 lected by Charles Darwin at Bahia Blanca, appears to be a well-defined 

 species, distinguished chiefly by the lesser number of transverse rows of 

 scales. In the Natural Museum is a specimen (No. 1709) collected by 

 Captain Page, U. S. N., in the expedition of the United States steamer 

 " Waterwitch" to Paraguay. The extremely pectinate scale, given in the 

 figure of Alosa pectinata, and upon which so mnch stress is laid by Mr. 

 Jenyns, is taken from one of the differentiated rows immediately in front 

 of the dorsal fin, which are alike pectinate in all species of the genus. 

 Two specimens belonging to the Museum of Comparative Zoology, col- 

 lected in the Eio Grande, agree thoroughly with Mr. Jenyns' description 

 and with the Paraguay specimens already referred to. 



Generic relations. 



38. Dr. Storer first referred the species to the genus Alosa, where it 

 stood until 18G1, when Professor Gill proposed for it a new genus, which 

 he named BreiioorUa, in honor of the Hon. J. Carson Brevoort, of New 

 York City. This genus is characterized by peculiarities of structure in 

 scales, gills, gill-rakers, and alimentary canal. 



A revision of the American species. 



39. The type of the genus Brevoortia of Gill is the species described 

 in 1802 by Latrobe under the name Clupea tyrannus, and later by Mitchill 

 under the name Clupea menhaden. As has already been indicated 

 (Proceedings U. S. National Museum, vol. 1, p. 5), the former name has 

 the prior claim to adoption, and the species must be called Brevoortia 

 ■tyrantius. Of this species there appear to be two geographical races or 

 subspecies. One of these is the typical form of the Atlantic coast of the 

 United States, the other a closely-allied form from the coast of Brazil, 

 already described by Spix under the name of Clnpanodon aureus. For 

 the species the name of Latrobe should be retained, and the two subspe- 

 cies may be distinguished as Brevoortia tyrannus, menhaden and Brevoortia 

 tyranmis, aurea: a third subspecies is temporarily adopted to include 

 some aberrant forms from Noank, Conn., for which the name Brevoortia 

 tyranmis hrevicaudata is proposed. On the coast of Patagonia and Para- 

 guay occurs a well marked species, described by Jenyns under the 

 name of Alosa pectinata. This species is readily distinguished by its 

 larger scales, which are arranged in 18 to 20 lateral rows, instead of 

 25 to 27, as in B. tyrannus. The generic relations of this species were 

 recognized many years ago by Professor Gill, and its name should stand 

 as Brevoortia pectinata, (Jenyns) Gill. 



*Tho Zoology of the Voyage of II. M. S. Beagle, &c. * * * Part IV. Fish. 

 * * * London, 1842., p. 135, pi. xxv. 



