194 HELICINACEA. 



I adhere to the opinion expressed in vol. i. that Hel. 

 rubella Green is identical with Hel. occulta^ and not with 

 this species. PfeifFer follows the opinion of Gould. 



The most northern locality at which this species has 

 been found is Tennessee. 



Helicina orbiculata Sowerby (Thes. Conch.) is not this 

 species. Pfeiffer refers it to Hel. nitida, a Cuban shell. 



Helicina vestita Guilding, in Sowerby's Thesaurus, No. 

 71, p. 14, tab. 1, fig. 42, appears to be the young of this 

 species. Its description is copied by PfeifFer, who was 

 unacquainted with the shell (Mon. Pneum. i. 353). It is 

 given below, while the figure is copied on my pi. 75, 

 fig. 19. 



H. VESTITA. T. globosa, tenui, concentrice lyrata, parva ; apertura 

 semi-lunari ; labio externo tenui. Globose, thin, concentrically ribbed, 

 small ; aperture semi-lunar, outer lip thin. North America. 



Helicina castanea Sowerby (1. c.) may also be an imma- 

 ture specimen of orbiculata. The figure of Sowerby is 

 copied on pi. 75, fig. 20, and his description given below. 

 PfeifFer refers it to a variety of Hel. subfusca Menke (Mon. 

 Pneum. i. 355). 



H. CASTANEA. Guilding ? T. H. orliculatce simili, sed Isevi, depressa 

 labio externo tenui. 



Like H. orbiculata^ but smooth and depressed, outer lip thin. North 

 America. 



Sowerby's figure of Hel. minuta is given pi. 75, fig. 18. 



HELICINA TROPICA IAHN. 

 PLATE LXXIII. Middle fig. of lower line. 



T. globosa, solida, lasvigata, alba ; spira fornicata, subacuminata ; 

 anfr. 5 convexiusculi, ultimus tumidus, antice non descendens ; apertura 

 fere verticalis, subsernicircularis, multo altior -quam lata ; columella 

 brevis, basi tuberculata, retrorsum in callum basalern diffusum, concolo- 

 rem, antrorsurn in peristoma crassum, reflexum, interdum duplicatim 

 continuata. Operc. ? Diam. maj. 8, rnin. 7, alt. 6 mill. (Pfr.) 



