FAMILY TURB1NIDJ3 NATICA. 123 



Natica PUSILLA. 



PLATE VII. FIG. 145. 



Natica pusilla. Say, Journ. Acad. Nat. Sc. Vol.2, p. 257. 

 JV. id. Gould, Invertebrata of Mass. p. 237, fig. 1GG. 



Description. Shell suboval, smooth, glossy, or with faint incremental and revolving lines. 

 Whorls four, regularly rounded : spire moderately elevated, obtuse ; suture distinct and deep ; 

 lip sharp, acute ; callus pressed laterally into the umbilicus, leaving a narrow curved linear 

 opening ; opercle horny. 



Color. Epidermis ash-colored ; underneath bluish white : throat white. 



Length, 0"5. Width, 0"8. 



I received specimens from several collections, labelled " JV. pusilla, Say," and gathered 

 many identical with them at Glasshouse point, near the city. I am now convinced that they 

 were either young of duplicata, or a species of Margarita, allied to, if not identical with 

 M. injlata. I have therefore adopted from Dr. Gould his figure and description, with the ob- 

 servation that the true pusilla as yet has only been obtained from the stomachs of fishes along 

 the coast, inhabiting deep water, and is probably a boreal species. 



Natica flava. 



N.flara. Godld, Am. Jour. Vol. 38, p. 196 ; Invertebrata of Mass. p. 239, fig. 162. 



Description. Shell globular, inflated, thin and light. Whorls four, rounded, slightly com- 

 pressed above near the suture, with very minute incremental and revolving striae : spire little 

 elevated. Pillar-lip with a curve in its middle ; the callus contracting and obliterating the 

 umbilicus, which is deeply indented. 



Color. Epidermis light yellowish ; white underneath : callus ivory white. 



Length, 0" 1 ; width rather less. 



This shell was obtained by Col. Totten from the Bank fishing grounds, and first described 

 by Dr. Gould. The absence of an umbilicus, which is one of the characters of the genus, 

 suggests the propriety of modifying it so as to admit this species, or to place it under a new 

 subgenus. There are three other American species, which figure in the catalogues under 

 the names of JV. canrena, Lam., alba and lunata, Say. The first is European, or rather 

 Asiatic. I can find no descriptions of the other two species, which are said to be found along 

 the Southern coast. For the fossil species, consult the Journal of the Academy of Natural 

 Sciences, Vols. 4 and 6. 



16* 



