THE PHILIPPINE LAND SHELLS OF THE GENUS 

 SCIHSTOLOMA. 



By Paul Bartsch, 



Curator, Division of Marine Invertebrafes, United States National Museum. 



In 1902 Dr. Willielm Kobelt, in his great work on the Cyclopho- 

 ridae ^ substitutes the name Schistoloma for CoptocJieilus Gould, which 

 is preoccupied by CoptocJiilus Amyot and Serville, 1843, a genus of 

 Hemiptera. 



Dr. Augustus A. Gould described the genus Coptocheilvs - in 1862, 

 defining it as follows: 



Shell chrysallidiform, acute, normally umbilicated, chestnut col- 

 ored; aperture almost disjunct from the spire; peristome more or less 

 double, with the internal lamina incised posteriorly. Operculum 

 (C. altum) corneous, multispiral, circular, and flat. Type: C. altum 

 Sowerby. 



There is a character in the operculum which Gould and Kobelt 

 seem to have overlooked, namely, that the spirals of the multispiral 

 operculum are fused only in the very center, the broad, expanded, 

 exceedingly thin edges being free and simply tightly appressed to 

 each other. See figures 5, 6, and 7 on plate 51. 



The Philippine shells group themselves readily under two divisions, 

 which we may designate as subgenera, with the following characters: 



Shell withi a narrow slit (breathing pore) near the jtmction of the inner lip and the 



parietal wall Schistoloma, ss. 



Shell without a slit in the peristome Hololoma, new subgenus. 



The subgenus ScJiistoloma is apparently confined to part of the 

 central islands of the Philippines. It extends from Mindoro and the 

 two little islands, Ilin and Semerara to the south of this, eastward to 

 Tablas, Romblon, and Sibuyan, while to the south, after apparently 

 jumping over Panay and Guimaras, it again occurs on Negros. 



The members of the subgenus arrange themselves into two groups. 

 The one possessing a large aperture and a broadly flaring, more or less 



1 Das Tierrelch, Konig. Preuss. Akad. Wiss. Berlin, vol. 16, p. 278. 



2 Proe. Bost. Soc. Nat. Hist., vol. 8, p. 282, 1802. 



Proceedings U. S. National Museum, Vol. 49— No. 2104. 



195 



