SCHIZOPOD CRUSTACEANS IN THE Ü. S. NATIONAL 

 MUSEUM. THE FAMILIES LOPHOGASTRIDiE AND 

 EUCOPIIDJE. 



By Arxold E. Ortmann, 



Of the Carnegie Museum, Pittsburg, Pennsylvania. 



INTRODUCTION. 



The paper submitted herewith forms the first installment of a series 

 of articles describing the Schizopod collections in the United States 

 National Museum. It treats of the families Lophogastridas and 

 Eucopiida?, which consist almost exclusively of deep-sea forms. The 

 material at hand, chiefly in the genus Gnathophausia, is so rich that 

 it has been possible to prepare a complete revision of that genus, and 

 it has been found that some characters, which were regarded hitherto 

 as of specific value, are but differences of age " in the same species. 

 This made it necessaiy to prove the changes of these characters with 

 age, and consequently, the discussion of some of the species is some- 

 what lengthy. 



Other families of the Schizopods will be taken up successively, and 

 the results will be published similarly, as the time at the disposal of 

 the writer will permit. 



Family LOPHOGASTRID^E G. O. Sars. 



i. LOPHOGASTER TYPICUS M. Sars. 



Oktmann, Bull. IT. S. Fish Comin. for 1903, Pt. 3, 1905, p. 967 (see for complete list 

 of literature). — Stebbixg, South African Crustacea, Pt. 2, Cape of Good Hope Dept. 

 Agric. 1902, p. 43. — Holt and Tattersall, Rep. Fisher. Ireland, Pt. 2, Append., 

 IV, 1905, p. 141. 



Of this species, material was available from two regions, from 

 which it was not hitherto known, namely, the western Atlantic (coast 

 of United States and Gulf of Mexico), and the western Pacific (Japan). 



The specimens from the western Atlantic are divided into three 

 sets: One from the coast of the Carolinas (Albatross stations Nos. 

 2314, 2601, 2602), consisting* of together 10 male« and 3 females; the 

 second from the Gulf of Mexico (Stations Nos. 2399, 2401, 2103), 



Proceedings U. S. National Museum, Vol. XXXI— No. 1480. 



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