134 OPEAS MAURITIANUM. 



tifications of these difficult forms were sometimes ill-founded. 

 His 0. davulinus from Bourbon was probably 0. mauri- 

 tianum, at least in part. 



Fig. 95 of pi. 17 represents a specimen from Maui, 

 Hawaiian Is., measuring length 12.7, diam. 3.5 mm. Like 

 the rest of the Opeas fauna of the Hawaiian group, it is 

 doubtless an immigrant there. I have also specimens col- 

 lected in Washington, D. C., probably from a greenhouse. 

 They were sent about twenty years ago by Rev. E. Lehnert, 

 a reliable and at that time well-known collector. 



Opeas prestoni Sykes of Ceylon differs by having the spire 

 a trifle less obese, more straightly tapering than the most 

 strongly characterized 0. mauritia.num, yet in a series of 

 both, these differences would not serve to separate them if 

 mixed. I doubt whether the nominal rank of a variety can 

 be upheld except on purely geographic grounds. 



Var. prestoni Sykes. PI. 17, figs. 98, 99, 100. 



Shell subperforate, long-cylindric, translucent, thin, cor- 

 neous or waxy-corneous, the apex somewhat obtuse; whorls 

 8!/2, plano-convex, longitudinally striated with growth lines, 

 the last whorl about nine-twentieths the total length; suture 

 well impressed; aperture elongate-ovate; peristome simple, 

 acute, the columellar margin narrowly renexed to the base, 

 nearly covering the perforation. Length 11, diam. 3.25, aper- 

 ture 3x1.8 mm. (Sykes). 



Ceylon: Uda Pussellawa (Preston). 



Opeas prestoni SYKES, Proc. Malac. Soc. Lond. iii, p. 73, 

 pi. 5, f. 4 (July, 1898). 



Fig. 98 is a copy of Sykes' original. Figs. 99, 100 are 

 from Ceylon specimens received from Mr. Collett. 



Var. obesispira Pilsbry. PI. 17, figs. 101, 102. 



Shell minutely perforate, turreted, translucent, corneous, 

 the columella visible through the shell; glossy, Avith faint, 

 arcuate wrinkles. Lateral outlines of the spire decidedly 

 convex above. Whorls about 8i/>, moderately convex, separ- 

 ated by impressed sutures, which appear to have a trans- 



