HELIX. 



Plate CXCl. 



[Shells cau8i<Icnilil,v magnified.] 



Species 1330. (Mus. Cuming.) 



Helix Tiiwaitesii. Ilel. tenia mltprofumii umbilical/!, 

 orbiculari-depresHa, niMincoided, pMiicido-vilred, lii- 

 tescenle ; spine milnrin impresnin ; aiifractibiia quimiue, 

 anguslii, coneexii, leii/e accmcenlibtis, inferni con- 

 tractu ; aperturd verticali-lioiari, subangiiald, labru 

 simplici. 



TnwAiTF.s's Helix. Shell rather deopiy iimbilicatcd, or- 

 bicularly depressed, somewhat discoid, transparent 

 glassy, yellowish ; sutures of the spire impressed ; 

 whorls five, narrow, convex, increasing slowly, con- 

 tracted at the lower part ; aperture vertically lunar, 

 rather narrow, lip simple. 



Pfeiffek, Pro. Zool. Soc. 1854. 



Hab. Ceylon ; Tliwaites. 



An interesting little glassy shell, of somewhat discoid 

 growth. 



Species 1337. (Mus. Cuming.) 



Helix MEDIOCRIS. Hel. iestd angtule nmbilicatd, orhi- 

 culari-planald, diicoided, ad peripkeriam liimidd, lenui, 

 earned, pallide luted ; spira; mtiiris impreuis; an- 

 fractibuH tribm ad quatuor ; aperturd transverse ovatd, 

 labru nimpliei. 



The middling Helix. Shell narrowly umbilieatcd, or- 

 bicularly flattened, discoid, swollen at the periphery, 

 thin, horny, pale yellow ; sutures of the spire im- 

 pressed ; whorls three to four ; aperture transversely 

 ovate, lip simple. 



Pfeiffer, Pro. Zool. Soc. 1854. 



Hab. Santa Anna, New Granada ; Bland. 



A flatly convoluted pale yellow-horny shell, of some- 

 what Nautiloid growth, the body-whorl being more than 

 usually immersed ^vithin the porch of the aperture. 



Species 1338. (Mus. Cuming.) 



Helix ammonoceras. Ilel. tesld latusimi aperti umbi- 

 licatd, diicoided, pellucido-rilred, liitmrciitc ; spird 

 pared, concavd; anfraclibu-s Iriius, ultimo Iraii-mrrrs^ 

 tumido ; aperturd trannterni ocati, lahro simplici. 



The AMMON-noRN Helix. Siiell very broadly openly 

 umbilieatcd, discoid, transparent glassy, yellowish ; 



August, 



spire small, concave ; whorls three, last transversely 

 swollen ; aperture transversely oval, lip simple. 



Pfeiffek, Pro. Zool. Soc. 1h54. 



llab. Santa Anna, New Granada ; Bland. 



Of still more Nautiloid growth than the preceding, from 

 the same locality, the spire being pressed coucavdy in. 



Species 1339. (Mus. Cuming.) 



Helix MOXONEMA. JM. testa subobtecli umiilicatd, gh- 

 boKO-pyraniidali, corueo-albd, subupard ; spird elerald ; 

 anfractibus septt'iii ad octo, concexin, obscure plicato- 

 slriatis, carind lenui Jili/omii ad peripheriam cingu- 

 latis ; aperturd transverse luuari, lahro simplici, ad 

 columellam reflexo. 



The one-thkeau Helix. Shell with a nearly covered 

 umbilicus, globosely pyramidal, homy-white, rather 

 opake ; spire raised ; whorls seven to eight, conves, 

 obscurely plicately striated, encircled at the periphery 

 with a fine thread-like kcol ; aperture transversely 

 lunar, lip simple, reflected at the columella. 



Benson, MS. (^lus. Cuming.) 



Ilab. Ceylon. 



Chiefly distinguished by a very minute thrcnd-like keel 

 encircling the periphery. 



Species 1340. (Mus. Cuming.) 



Helix Qcitensis. Uel. tesld vix umbHicala, globoto- 



■ conoided, peltucido-vilred, Itrrigatd ; spird eonrexd ; 



an/ractiius qtuituor ad quinque, rotundnlis ; aperturd 



lunato-circulari, labro simplici, ad coiumfllam reflexo. 



The Quito Helix. Shell scarcely umbilieatcd, globosely 

 conoid, trausparcut glassy, smooth ; spire convex ; 

 whorls four to five, rounded ; aperture lunar-circular, 

 lip simple, a little reflected at the columella. 



Pfeiffer, Pro. Zool. Soc. 1854. 



llab. Quito. 



A little glas-sy species, of simple conoid structure, 

 scareclv umbilieatcd. 



Species 1341. (Mus. Cuming.) 

 Helix PirrieaNa. Ilel. tesld globoso-pyramidali, pel- 

 1854. 



