314 BULLETIN OF THE 



Corbula Swiftiana C. B. Adams. 



Corhula Swiftiana C. B. Adams, L c. p. 236, 1852 ; Dall, Bull. M. C. Z., IX. p. 114, 



1881. 



Plate II. FigB. 5 a - 5 c. 



Habitat. Sigsbee, off Havana, 182 and 450 fnis., living; oflf Sombrero, 72 

 fms. 



Identified and figured from the types. Lon. of shell 10 4 mm. 



Corbula Dietziana C. B. Adams. 



Corhula Dietziana C. B. Adams, 1. c, p. 2-35, 1852 ; Dall, Bull. M. C. Z., IX. p. 114. 

 Corbula Blandiana C. B. Adams, 1. c, p. 234 (= young stage of C. Dietziana, Ad.). 



Plate I. Figs. 5, 5 a, 5 b. 



Habitat. West coast of Florida, 30 fms. ; off Sombrero, 72 fms. ; Barbados, 

 100 fms. ; Gordon Key, 68 fms. 

 Identified and figured from the types. Lon. of shell 10.7 mm. 



Corbula disparilis D'ORnioNT. 



Corhula disparilis D'Orb., 1846; Dall, Bull. M. C. Z., IX. p. 115, 1881. 

 Corbula Philippii Smith, Chall. Rep., p. 33, pi. vii. figs. 4, 4 a, 4 b, 1885. 

 Corbula operculata Philippi, Zeitsch. Mai., V. p. 13, 1849. 



Plate T. Figs. 4, 4 a, 4 b. 



Habitat. Off the west coast of Florida, 30 and 50 fms. ; Station 12, 36 fms. ; 

 off Sombrero, 72 fms. ; Station 36, 84 fms. ; Barbados, Station 287, etc., 7^ to 

 100 fms. ; Sigsbee, off Havana, 127 and 450 fms.; Station 2, 805 fms. 



This species closely resembles several exotic and fos.sil forms ; among the 

 former may be mentioned Corbula nucleus L. ; among the latter, C. oniscus 

 Conrad (Eocene of the United States) and C. parsura of Stoliczka, from the 

 Trichinopoly beds (Cretaceous of India), as well as some from the Danish 

 ligniferous strata. 



Those who consult D'Orbigny's figures will observe that they differ from the 

 shell figured by my friend Smith in representing the valves as nearly equal, 

 and also in the absence of the epidermal radiations on the smaller valve and 

 the carina on the larger one. But I infer from D'Orbigny'.s remarks, that he 

 had only separated valves, and probably those which had lost their epidermis; 

 and it is probable that the artist represented two valves together which did not 

 belong together. The carina is a variable feature in this species, as in C. nu- 

 cleus. At all events, the specimens I have are certainly the same as G. Phi- 

 lippii Smith, and I believe them to be the species described by D'Orbigny. 



