26S F. Stoliczka — On t'he Cyelostomacea of Penang. [Xo. 3, 



Megalomastoma sectilabettm, Gould. PI. X, Fig. 13. 



Penang specimens agree with those from Tavoy in having a smaller- 

 aperture and a slightly slenderer spire, with somewhat convex sides, while in 

 31. anostoma from Borneo the spire is more regularly conical and the aper- 

 ture larger. 



Animal blackish grey with a slight reddish tinge ; the edges of the 

 foot, including the posterior end and the tentacles are vermilion, tips of 

 rostrum pale grey. The length of the foot equals about three fourth of 

 that of the shell when the animal moves about ; the entire body is rather 

 distinctly warty, but no well defined pedal row exists ; the rostrum is 

 adpressed to the foot, strongly wrinkled and cleft at the end ; posterior 

 end of foot obtusely pointed, eyes small, the bulgings united at their bases 

 to the tentacles. The mantle is pale, entire, closely attached to the 

 peristome of the shell, and not protruding beyond it. 



Operculum horny, circular, composed of several spiral layers arranged 

 round a slightly thickened or mammillated centre so that the width of each 

 lamina equals the radius of the whole operculum. This structure is some- 

 what peculiar, it agrees with that of the South Indian Oataulus recurvatus, 

 but not with that of the other Gatauli or Ilegalostomata examined ; in all 

 these the operculum is distinctly multispiral. 



The species occurs at elevations from 400 to about 2400 feet on the 

 Penang hill, but it is evidently a very scarce shell ; I found only one live 

 .specimen at the top of the hill. 



Fam. — DlPLOMMATINEDJi. Sub-fam. Al/YCiEIIOE. 

 AlYCJlTJS GIBBOSULUS, n. Sp. PI. X, Fig. 14. 



A. testa gibboso turrita, anguste umbilicata, violaceo rubente, ultimo an- 

 fractu pallidiore, lutescente, apice albescente ; anfractibus quinque, valde 

 couvexis, sutura profunda et simplici junctis ; primo Icevigato, tribus sequen- 

 tibus transversim densissime striato-costellatis atque spiraliter striatis, 

 ultimo gibbose inflato, paulo distinctius costellato, prope aperturam breviter 

 sed valde constricto, sub -Icevigato, vix defexo, post constrictionem tubulo 

 tenui, eirciter duo ad tres m.m. longo, nonnunquam fere immerso, instructo ; 

 opertura circulari, modice lata, in adolescentibus margine simplici undigue 

 expansiusculo circumdata, in adultis bilabiata, labio interno extus tubuli- 

 forme producto, crassiusculo, externo dilatato atque tenui. Operculum 

 solidum, latere interno corneo, convexiusculo, medio subniammillato, onulti- 

 spirato, impressione musculari transverse ovata atque excentrica instructo, 

 externo calcareo, concaviusculo, in superficie irregulariter rugoso. Diam. 

 maj. 9'2, diam. mm. 7, alt. testes 96 ; diam. apert. int. 3*8, extemce 4 - 8 m.m. 



In general character this interesting new species closely resembles the 

 type of the genus, Al. gibbus, Fer., but the latter conspicuously differs by 



