MUSEUM OF COMPARATIVE ZOOLOGY. 293 



Xatica prorima Sowerby, Tlicsaurua, Nalica, pi. viii. flj?. Ill, not of C. B. Adams. 

 1 Nalica rujilabris Reeve, Conch. Icon. Natica, fig. 10;J, 1805. 



Habitat. Barbados, 100 fms. Key West, Pickerinrj. Gulf of Mexico, be- 

 tween Mississippi delta and Cedar Keys, in 2G fnis., U. S. Fish Commission. 



This form is generally more elevated, than maroccana, and its coloring more 

 like Lunatia triscriata. The nucleus is always minute, and generally dark 

 brown. It is related to N. maroccana, but its operculum has only a single 

 narrow undivided marginal rib separated by a narrow groove from the inner 

 area, so that I can assert that the name is not a synonym. It will probably 

 include N. limacina Jousseaume, but of that, again, I have seen no authentic 

 specimen, while rufdahris is in the same category. N. lacernula Orbigny is 

 doubtless synonymous with livida, and probably N. pulchella Pfr. also belongs 

 here. 



Section NATICA s. s. 

 Operculum shelly, externally multisulcate. 



Natica canrena Lamarck. 



This well known and characteristic species was not obtained by the Blake, 

 but is known from authentic sources to extend from Rio Janeiro to the An- 

 tilles, and from the Antilles to Cape Hatteras. It has a large and pellucid 

 nucleus, which will always serve to distinguish it from species of the maroccana 

 group in the absence of the very characteristic operculum. 



Natica castrensis n. s. 



Shell four-whorled, thin, light, white painted with yellow brown. Nucleus 

 large, lucid; an opaque white band in front of the suture with irregular brown 

 flammules; a peripheral series of distant small obscure brown spots ; base, 

 callus, umbilicus, and aperture opaque spotless white, remainder translucent 

 white with a network of extremely fine lines and spaces, so disposed as to form 

 spirally directed "tent" shaped white markings on a brownish ground, re- 

 calling the pattern of Conus gloria-mar is, the apices of the little white triangles 

 all pointing toward the aperture; whorls extremely round, the suture conse- 

 quently well marked, and almost channelled; general form about like that of 

 N. canrena ; umbilicus with a single moderate funicular cord, with subequal 

 grooves above and below it, ending in a small callus with a notch behind it, 

 and a bigger body callus behind that. Alt. 12.5, lat. 12.5 mm. 



Habitat. Barbados, 100 fms. Off Sombrero, in 54 fms. Station 152, Flan- 

 negan's Passage, in 27 fms. Key West, U. S. Nat. Mus. Coll. 



The painting of this species recalls that of A*^. vittata Gmelin (which is a Lu- 

 imtia), but is much more delicate and elegant. The netted painting can only 

 be seen by close inspection. The umbilical region differs from that of N. can- 



