18 F. Stoliczka — Land-shells of Penang Island. [No. 1, 



a distinct denticle on either side, and the last laterals with two small unequal 

 cusps ; all have the basal plate obtusely narrowed outwardly. 



The genital organs are very similar to those of M. indicus, Benson, but 

 much more slender ; the araatorial gland is very thin (in a j^oung specimen), 

 there is a small coecal appendage on the vas deferens, and a flagellum at the 

 base of the penis, just before a swelling filled with calcareous particles. 



MiCEOCYSTIS* PALMICOLA, n. Sp. PI. i. fig. 10. 



M. testa late conica, tenui, cornea, angustissime umbilicata ; anfracti- 

 bus quinque, gradatim accrescentibus, convexiusculis, sutura simplici junctis, 

 supra splendore albide sericino, transversim oblique, minutissime atque con- 

 fertissime, striolatis, ultimo ad peripheriam acute angulato ; basi convexius- 

 cula, olivaceo nitita ; apertura subsemilunari, extus angulata, obliqua ; labro 

 tenui, simplici, ad basin recedente, ad umbilicum reflexo ; labio tenuissimo, 

 vix distinguendo. Speciminis maximi diam. maj. 2*8, d. minor 2 6, alt. 2*2, 

 diam. apert. 1"7, ejusd. alt. 095 m.m. 



Sah. — Penang, sub corticem Coccos nuciferm, baud frequens. 



The shell is distinguished from allied species by its comparatively 

 sharply angular last whorl, slightly inflated base and by the peculiar silky 

 and very finely striated upper sui^face. 



The animal when fully extended equals in length about four diameters 

 of the shell ; it is rather dark brownish grey, darkest on the tentacles and 

 on the rostrum ; posterior gland superseded by a small horn. 



HELiCAEiONf PERMOLLE, n. sp. PL i, fig. 11 and pi. ii, figs, 21-23. 



H. testa depresse inflateque conoidea, tenuissima, fere membranacea, 

 translucente, pallide lutescente, vix perforata, spira ultimo anfractu multo 

 breviore ; anfractibus 4*5, rapide accrescentibus, ad suturam simplicem ad- 

 pressis, nitidis, convexiusculis, ultimo inflato, ad peripheriam rotundato, 

 transversim lente arcuateque striatulo, ad basin striis spiralibus sub-obsoletis 

 notato ; apertura lunari, valde obliqua, labio albescente, minutissime puncti- 

 culato, labro tenuissimo, simplici, ad basin valde recedente, ad marginem 

 interiorem umbilici breviter reflexiusculo. Diam. maj. 8*4, d. min. T*!*, alt. 

 6*3 ; alt. apert. cum perist. 4, ejusd. lat. 4*3 m.m. 



The rather strongly elevated spire, and the membranaceous and trans- 

 parent structure of the shell, separate this species from the numerous allied 

 forms of the Philippines. The species is rare ; I only obtained about half 

 a dozen specimens on low bushes or between old vegetable matter on the 

 ground, about 500 feet above the sea, on Penang hill. 



* Microcystis, Beck. Comp. Semper iu Reis. Arcli. Philipp., pt. II, vol. iii, 1870. 

 p. 43, and Stoliczka in J. A. S. B., vol. xl, pt. II, p. 251. 



t Semper, Reisen Arcliip. der Philippinen, vol. iii, p. 20. 



