HELICINA. 195 



SYNONYMS AND REFERENCES. 



Helicina tropica IAHN in Chemnitz, ed. 2, p. 37, pi. iv. figs. 9, 10. 



PFEIFFER, Mon. Pneum. Viv. i. 375; ii. 199. 



GRAY and PFEIFFER, Brit. Mus. Phan. p. 271. 



TROSCHEL, Gebiss d. Schn. p. 81, pi. v. fig. 9, (teste Pfr.) 

 Helicina Ambeliana SOWERBY, T hes. Tab. i. fig. 19, nee ROISSY. 



Remarks. The figure referred to is evidently this spe- 

 cies, which is common in Texas. It appears to me to 

 run imperceptibly into Hel. orbiculata, and will, in all 

 probability, prove one of its many varieties. Indeed, 

 PfeifFer observes, " Ex icone Sayana hanc speciem se- 

 quent! (orbiculatce) identicam suspicor." 



Helicina Ambeliana Sowerby (not of DeRoissy) is 

 referred to a " var. i3 flavida, vel rubella, interdum subfas- 

 ciata," by PfeifTer, to which also he refers Chemnitz's 

 variety (fig. 22). Sowerby's figure is given (pi. 75, fig. 

 15), and his description here follows. 



H. AMBELIANA. T. conica, kevi, spiraliter tenuissime striata ; aper- 

 tura semi-lunari ; labio externo crasso, reflexo, rotundato ; operculo cor- 

 neo. 



Rather conical, globose, nearly smooth, with the aperture semilunar, 

 and the outer lip thickened, reflected, and rounded ; operculum horny. 

 Antilles and Texas. 



HELICINA SUBGLOBULOSA POEY. 

 PLATE LXXV. FIGURE 17. 



T. globoso-conica, solida, striatula, parum nitida, alba, unicolor, vel 

 zonis 2* run's ornata : altera lata prope suturam, altera angusta prope 

 peripheriam ; spira convexo-conica, acuminatiuscula ; anfr. 6, primi 

 planuli, penultinms convexior, subbiangulatus, ultimus subcarinatus, basi 

 parum convexus ; coluniella brevis, arcuata, sursum dilatata, linea im- 

 pressa munita, callum eniittens tenuem, diffusum ; apertura parum obli- 

 qua, irregulariter semiovalis ; perist. latum, angulatim patens, subexca- 

 vatum, ad utramque insertionem attenuatum. Operc. ? Diam. maj. 10, 

 min. 8J, alt. 7 mill. (Pfeiffer.) 



