In- 



teriorly close to the last volution ; peritreme thin, anteriorly very 

 slightly reflected ; umbilicus very large, showing internally the 

 four volutions. 



The shell is somewhat diaphanous, so that the white and dark- 

 brown zones are distinctly seen within the aperture. 

 Columbia. Mus. Cuming. 



182. Cyclostoma texturatum (Tab. Suppl. xxxi. a, f. 303), 

 nobis. 



C. testa depresso-suborbiculari, albida, epidcrmide crassiuscula 

 olivaceo-brunnea induta ; spira brevissima, obtusa, anfractibus 

 ([uinque, rotundatis, irregulariter rugulosis seu sulcis irregularibus 

 undulatis circumdatis ; sutura distincta ; apertura fere circulari, 

 postice prope anfractum ultimum subangulari, intus albicante ; 

 peritremate tenui ; umbilico maximo. 



Shell suborbicular, depressed, whitish, coated with a thickish 

 olive-brown epidermis ; spire very short, obtuse ; volutions five, 

 rounded, entirely covered with irregular undulated grooves, giviug 

 it somewhat the appearance of being woven ; suture distinct ; 

 aperture nearly circular, slightly angular posteriorly close to the 

 last volution, whitish within ; peritreme thin ; umbilicus very 

 large. 



Prom the Province of Guatemala, Central America. Cuming. 



183. Cyclostoma incomptum (Tab. Suppl. xxxi. a, f. 298, 

 299), nobis. 



C. testa depresso-suborbiculari, alba, epidermidc olivaceo-brun- 

 nea induta ; spira brevi, obtusa ; anfractibus 44, rotundatis, 

 oblique lineis incrementi validis striatis ; sutura distincta ; aper- 

 I ura fere circulari, postice prope ultimum anfractum sinuata, extus 

 I uberculam fornicatam formante ; peritremate antice incrassata ; 

 umbilico magno. 



Shell suborbicular, depressed, white, covered with an olive- 

 brown epidermis ; spire short, obtuse ; volutions 4|, rounded, 

 obliquely striated by the strongly marked lines of growth ; suture 

 distinct ; aperture nearly circular, with a sinus posteriorly close 

 to the last volution, forming a vaulted tubercle externally ; peri- 

 treme thin, a little thickened in front ; umbilicus very large. 



This is one of the genus Pteroc/jclos, of Penson ; we do not 

 know its locality, but suppose it to be Indian. It is in Mr. 

 Cuming's Collection. 



