William J. Richards

Systematics of the Percid Fishes of the Etheostoma thalassinum Species Group with Comments on the Subgenus Etheostoma

related. E. swannanoa, from the headwaters of the Tennessee River system, exhibits several specialized features: absence of palatine teeth, reduction in number of prevomerine teeth, and presence of a basal orangered band in the spinous dorsal fin. These features among others relate this group to E. blennioides.

Internal Development of Young Tunas of the Genera Katsuwonus, Euthynnus, Auxis, and Thunnus (Pisces, Scombridae)

Young of eight species representing four genera of Atlantic scombrids were studied using sectioned organs and tissues. Some interspecific differences were found in the nucleation of the central nervous system, development of the swimbladder, size of the postcardinal vein, meninx pigmentation, and length of the kidney and liver. Differences, however, were at the generic level and little difference was found between the closely related species.

Percina lenticula, a New Percid Fish, with a Redescription of the Subgenus Hadropterus

T HE discovery of Percina lenticula, a distinctive new species from the Alabama River basin, brings to 3 the number of species in the subgenus Hadropterus. In addition to describing the new species, it seems desirable here to diagnose and redescribe the subgenus and to review its nomenclatural history. The monotypic genus Hadropterus was erected by Agassiz (1854) when he described H. nigrofasciatus from near Mobile, Alabama. Since that time, Hadropterus has been used variously as a genus or subgenus and has included a fluctuating number of species. The species and subspecies (including valid and nominal forms) which have been assigned to the genus or subgenus Hadropterus are listed in Table 1. Jordan and Gilbert (1883) added Cottogaster aurantiaca Cope to the genus Hadropterus. Jordan and Evermann (1896) included 4 subgenera (Alvordius, Hadropterus, Serraria, and Ericosma) and 12 forms in the genus Hadropterus. Jordan, Evermann, and Clark (1930) regarded Hadropterus as being monotypic. Bailey (1951) directly or inferentially placed 8 generic names under the genus Hadropterus and later synonymized (Bailey, Winn, and

Elopoid leptocephali from Angolan waters

tracted great interest among ichthyologists because of their unusual leptocephalus development, a stage found in no other group but eels. Forked tails of the elopoid leptocephali provide an easy means of separating them from eel leptocephali, which have isocercal tails. Knowledge of larvae from the eastern Atlantic is rare, but personnel aboard the R/V UNDAUNTED recently collected 103 leptocephali of the genera Albula, Elops, Megalops, and Pterothrissus from four locations in Angolan (West Africa) waters. This report contains descriptions of these larval forms. In addition one very young specimen of Pterothrissus collected by the R/V PILLSBURY in the Gulf of Guinea is described. All specimens collected by the R/V UNDAUNTED were deposited in the fish collection of the Bureau of Commercial Fish-