MUSEUM OF COMPARATIVE ZOOLOGY. 261 



.4. crenata. But the lens, or crenata, of the same size as A. Smithii, is longer, 

 aiuch flatter, and usually not crenate ; the waves or ribs are of a diff'erent 

 form, and the color is a more ruddy brown. 



Astarte nana, n. s.? 



1 Astarte nana Jeffreys, Smith, Obs. on the Genus Astarte, Leeds Journal of Con- 

 chology, p. 213, 1881. (Gulf of Florida, 60 fms., Pourtales.) 



Plate VII. Figs. 6 a, 6 b. 



I have not been able to find, as yet, in the Jeffreys collection, any specimens 

 of his Astarte nana ; nor have I seen anything more in the way of description 

 than the four and a half lines given by Mr. Smith. The locality is suggestive, 

 the specimens were collected by Pourtales, and the features mentioned by 

 Smith, as far as they go, agree with the present form, though insufficient for 

 identification. I prefer to use the name nana, and if hereafter it should prove 

 that it is not Jefl'reys' nana, another name can be applied to it. The shell is 

 well represented by the figure ; it is about the same color as A. Smithii, but 

 somewhat larger, flatter, with the beaks more erect and more prominent ; it 

 has about thirty uniform concentric ribs separated by equal intervals and cover- 

 ing the entire shell except the lunule : the latter is smooth, but not circum- 

 scribed by a line ; there is a depvession along the dorsum, but hardly a dorsal 

 area as distinguished from the rest of the shell. The inner margins are smooth 

 at all ages observed ; the muscular scars are proportionally larger, and the 

 pallial line further from the margin than in A. Smithii; the lunular region 

 is longer and not so deep ; the teeth, though larger, are the same as in that 

 species. Lon. of shell 8.2 ; alt. 7.8 ; diameter 4.1 mm. 



Habitat. Sombrero, 54 fms.; Station 36, Gulf of Mexico, Lat. 23° 13', Lon. 

 89° 16' W., 84 fms., bottom temperature 60°.0 F. OS' the Carolina coast nearly 

 to Cape Hatteras, valves at various depths, U. S. Fish Commission. 



This shell rnay be crenulate at some age ; it is not, however, like the pre- 

 ceding species, crenulate at all ages. Some of the Fish Commission specimens, 

 apparently of the same species, have the interior of a rose pink or light yel- 

 lowish brown color. 



Genus CIRCE Schcmachek. 

 ScBGENus GOULDIA C. B. Adams. 



<GouIdia C. B. Adams, Cat. Coll., p. 20, 1847. 



< Thetis C. B. Adams, Proc. Bost. Soc. Nat. Hist., p. 9, 1845, non Sowerby. 



Lioconcha Morch, Cat. Yoldi, pt. ii. p. 26, 1853. 



Gouldia Dall, P. Z. S., 1879, p. 131 ; Bull. M. C. Z., IX. p. 128, 1881. 



<Circe E. A. Smith, Chall. Rep., pp. 221-223, 1885; P. Z. S., 1881, p. 489. 



In 1879, in a discussion of the claims of the name Gouldia to retention, 

 I showed, while two forms were included by Prof. Adams in his genus, that 



