NATICA spadicea, 

 Banded Natica, 



Generic Character. 

 Testa subglohosa seu ovalis, umhiUcata. Spira depressa, brevissima. 

 Columella umbilici medio terminans. Apertura sefniorhicularis, oper- 

 culo corneo vel testaceo clausa. Animal marinum, pede maxima ; 

 oculis ad basin duorum tentaculorum simplicium positis. 

 Typus Genericus Nerita Glaucina Pennant. 

 Shell nearly globose, or oval, umbilicated. Spire depressed, very 

 small. Columella terminating in the middle of the umbilicus. 

 Aperture semi-circular, operculum either horny or testaceous. 

 Animal marine, with a large foot ; the eyes placed at the base 

 of two simple tentacula. 



Generic Type Nerita Glaucina Pennant, &c. 



Specific Character. 



N. testd sub-globosdy fused, alhofulvoquefusciatd,juxta suturam striatd; 

 labia exteriore supra leviter emarginatu ; umbilico magno, aperto ; 

 columelld obsolete terminante. 



Shell sub-globose, striated near the suture, brown, banded with 

 white and fulvous ; outer lip above slightly emarginate ; um- 

 bilicus large, open ; pillar termination nearly obsolete. 



Martini 5. pi. 187. Jig. 1 872 4' 3.Jig. 1 874 SrB'^.pL ISS.Jig. 1 896, 8 <5- 9. 



Seba, pi. 38. Jg. 66. pL4\. Jig. 14, 15. 



1 HE Shells of this genus are composed of such of the Lin- 

 nasan Merits as are umbilicated, from which latter they essen- 

 tially differ, both in the organization of the animal and the 

 construction of the shell, which is either closed by a shelly or 

 horny operculum. 



The species are numerous, and are found both in temperate 

 and tropical seas ; two or three inhabit our own coasts, but 

 by far the greater number are found in the Asiatic Ocean. 

 They are subject to variation in their colour; and this, 

 joined with a general resemblance in form, has rendered 

 the discrimination of the species very difficult. I have, how- 

 ever, remarked, that the various modifications of the umbilicus, 

 and the termination of the pillar (which is indicated in many 

 species by an elevated ridge or rib within the umbilicus) is a 

 certain and constant indication, presenting the same pecu- 

 liarity through all the individuals of a species, even in the 

 young state. This termination of the pillar has been mistaken 

 for the inner lip, which, on the contrary, is always above the 

 umbilicus, which, if closed, is not closed by the lip, but by 

 the thickened termination of the pillar or columella. 



The two most striking varieties are here- figured of this 

 species, which is sufficiently described in the specific character. 

 I believe it is found both in the Mediterranean and Red Seas, 



PI. 75. 



