HELICINA. 195 



SYNONYMS AND REFERENCES. 



IJelicina 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.) 

 Eelicina Ambeliana Sowerby, Thes. Tab. i. fig. 19, nee EoissY. 



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- 

 quenti [orhiculatce) identicam suspicor." 



Helicina Ambeliana Sowerby (not of DeRoissy) is 

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

 ciata," by Pfeiffer, 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, Isevi, spiraliter tenuissime striata ; aper- 

 tura seini-lunari ; labio externo crasso, reflexo, rotundato ; oj^erculo cor- 

 neo. 



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

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

 Antilles and Texas. 



HEIilCINA SUBGLOBULOSA Poey. 



Plate LXXV. Figure 17. 



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

 zonis 2 rufis ornata : altera lata prope suturam, altera angusta prope 

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

 planuli, penultimus convexior, subbiangulatus, ultimus subcarinatus, basi 

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

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

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

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

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



