﻿P L A N A X I S, 



Genus PLANAXIS. L, 



soli,la. 



"/"'■•'/" 



,,..„,,. ,-«/»>■ ,lr„l„i,:j;r„l„, „„l„-r /,r//, rr,i,i<:lifrnt, 

 finiirijiiiata; rolumrlla subarcnata, iilanabi, ad 

 termiiunn truneata ; operculum ovato-obloiujum, 

 inii.^/iirali; niicleo fere terminaU. 

 Slu'll iivately conical, solid, generally spirally grooved; 

 >|iire for the most part short, conical; aperture 

 ratiier trigonal, tooth-ridged within, with a 

 slight canal and notch in front ; coluniella 

 slightly arched, flattened, trnnoated at the end ; 

 operculum ovate-oblong, with one-whorled spire, 

 nucleus nearly terminal. 

 Few genera so restricted in numbers are so widely 

 spread in their habitats. We have identified 39 

 species, of which the greater number are tenants of 

 .\ustralian. South Sea Island, and Philippine groups. 

 The Red Sea and Persian Gulf, the Mauritius and 

 West Indies contribute their portion ; the Chinese 

 and 1 ndian Seas have several, but there are no Euro- 

 pean species. The animals are marine, but partly 

 amphibious, and spend a large portion of their exist- 

 ence above water. The slight canal and notch at the 

 front of the aperture, and the flattened columella 

 terminating in a notch, render this genus character- 

 y distinguishable. 



within. 

 S.Mrnt. Pruc. Zdol. 8oc. 187-, p. 88. 

 Ill lb. Arracan. 



In the specimens from which the description was 

 taken (no others being known) the upper whorls are 

 much corroded, and the bodj- whorl being smooth, 

 with spiral grooves almost obsolete above, gives the 

 remaininar surface a sort of enamelled uiiiiearance. 



species 



(Mus. Brit. 



istic and 



PL.4NAXIS CASTANEUS. Fla. testa subpijfifuniu, la-vi<jaAa, 

 castaneii, spirnliter tenuiter striata, longitmlinu- 

 Hfrr nhUifw !ii,hl!rafa: ^plra rlrvafn, nrmuhiala, 

 ,i„fr.irl,l.„,,r,n<.,;„n; /■;»sr»/;,s-; iili: .un hiilh:f.,n„i , 

 ap,',i,n;l /,„rr,l, l„br.. iiilus 7.,lr„t;,-„hiln, w, ,,-,,:,„■ 

 Icuiii, eoliimj'lli'i Kiihitrciiiitd, inj'n'i snlien'jiaiitur. 



The cHEiSTNCT Planaxis. Shell somewhat pyriform, 

 smooth, chestnut, spirally finely stri.ited, longi- 

 tudinally obliquely slightly ridged ; spire raised, 

 acuminated, whorls six, rather convex ; end bulb- 

 shaped, aperture small, outer lip seven-tiMitlu-d 

 within, margin thin, columella slightly urelied, 

 rather expanded below. 



S.MiTH. Proc. Zool Soc. 187-2, p. 41. 



][ab. — ? 



Species I. (Mus. Hanley.) 

 PlanaxiS ENCAtlSTlCDS. Phi. testd rrassd, brevi, albidd. 

 cceridixd, fusmqxie nchidatd et fasciald, Iwviijatd ; 



anfractibus 



ad ,-nde 



ultimo ventria 



infra mediiim mtinidi', nd suturam anguste angu- 

 lato, mgro-piuirtiilii, sjiiriditer, tenuiter, distanter, 

 infra ariguliini rutidi' .ttdcato ; aperturd castanrd, 

 ■•ohmii'Ud brrvi, late triincatd, prope suturam 

 validi'. callosd; labrx iidi'is distanter et validi- 

 dcitato-liratn. 

 The enamelled Planaxis. Shell thick, short, whitish, 

 clouded, .and banded with blue and brown, 

 smooth; whorls six to seven, the last ventricose, 

 roundly angular below the middle, and narrowly 

 at the suture ; black-spotted, spirally, finely, 

 distantly grooved, strongly below the angle ; 

 aperture chestnut, columella short, broadly 

 truncated, with a strong callus near the suture. 



Species 3. (Mus. Brit.) 



PlanaXIS CRASSISPIRA. Pla. test,! i<hlnn,jii, siihdistanlci- 

 ."piraliter sulcata, grisea, ,inji.:j,ii,n-tiitd ; apird 

 elevatd, crassii, subcyliiidriril^ nlflnsd ,■ aiifrartu 

 idtimo obtus'i: (iiiijuhitii, aprrtiira pitnd, sahfriiitntd , 

 columella itllnt. hifru Inir pm,! i,d,'i. labm iidi's 

 ralide dentafo. 



The THICK-SI'IRED Pi,.\naxis. Shell oblong, rather 

 distantly spirally grooved, grey, spotted with 

 black ; spire eleviited, tliick, subcylindrical, ob- 

 tuse ; last whorl obtusely angular ; aperture 

 small, subtrigonal, columella white, broadly 

 produced below ; outer lip strongly toothed 

 witbin. 



Smith. Proc. Zool. Soc. 1872, p. 3!». 



Hab. ? 



Diflering from Planaxis siilcatu 

 straight-sided form. 



the narrow. 



