NO. 2104 LAND SHELLS OF THE GENUS SCHISTOLOMA—BARTSCH. 197 



Lip with slit — Continued. 

 Aperture smaller, with the peristome flatly expanded. 



Peristome chocolate brown . tablasensis. 



Peristome not chocolate brown. 

 Peristome flesh-colored to pale brown. 



Shell small, average diameter 9.37 mm mcgregori. 



Shell larger, average diameter 10.46 mm webbi. 



Lip without slit (Hololoma). 



Average altitude 28.4 mm corojiensis. 



Average altitude 25.7 mm quadrasi. 



SCHISTOLOMA (SCHISTOLOMA) ALTA Sowerby. 



Cydnstoma altum Sowerby, Proc. Zool. Soc. London, p. 84, 1842. 

 Megalomastoma altutn Pfepfer, Zeitschr. f. Mai., p. 109, 1847. 

 Coptochcilus altum Gould, Proc. Boston Soc. Nat. Hist., vol. 8, p. 282, 1862. 

 Coptochilus altum, var. protracta Kobelt and Mollendorfp, Nachrbl. Deut. 



Malak. Ges., vol. 29, p. 141, 1897 {nomen nudum) . 

 Schistoloma altum Kobelt, Das Tierreich, vol. 16, p. 278, 1902. 



Shell elongate conic, chocolate brown, with the peristome ranging 

 from brown to flesh-colored. Nuclear whorls a little more than two, 

 smooth, well rounded, polished, separated by a well-impressed su- 

 ture. Postnuclear whorls well rounded, marked by decidedly retrac- 

 tive and strongly developed, closely spaced lines of growth. The spiral 

 sculpture is variable, ranging from a few, irregularly scattered, incised 

 lines to closely spaced, fine, spiral striations, which may cover the entire 

 surface. Sutures somewhat constricted. Periphery of the last whorl 

 well rounded. Base well rounded, narrowly umbihcated; a bounding 

 fasciole to the umbilicus may be present or absent. Aperture large, 

 irregularly oval; peristome complete, decidedly expanded, the flaring 

 edge being irregularly curved, that is, not in one plane. There is an 

 inner lip which may flow over and fuse with the outer lip anteriorly, 

 bemg more distinct on the parietal side; this inner lip bears a notch 

 at the junction of the columella and the parietal wall; parietal lip 

 adnate to the body whorl. 



The species breaks up into five subspecies, wliich are characterized 

 chiefly by the measurements and coloration noted below. 



SCmSTOLOMA (SCHISTOLOMA) ALTA ALTA Sowerby. 

 Plate 51, figs. 9 and 11. 



Cyclostoma altum Sowerby, Proc. Zool. Soc. London, p. 84, 1842. 

 Megalomastoma altum Pfepfer, Zeitschr. f. Mai., p. 109, 1847. 

 Coptocheilus altum Gould, Proc. Boston Soc. Nat. Hist., vol. 8, p. 282, 1862. 

 Schistoloma altum Kobelt, Das Tierreich, vol. 16, p. 278, 1902. 



In this subspecies, which comes from the Island of Negros, the peri- 

 stome is very thick. The lip is usually flesh-colored, though at times 

 pale brown. 



