PHILIPPINE LAND MOLLUSKS 



341 



and in which the base is slightly inflated and well rounded. The 

 incremental sculpture is almost riblike and decidedly retractively 

 curved on the last whorl, but the impressed wrinkles are only poorly 

 shown. It can be at once distinguished from Obba marm&rata 

 etijana by its being decidedly depressed, by having the aperture 

 much smaller and much more narrowly oval, and by having the 

 base almost free from wrinkles. 



Type. — U.S.N.M. No. 312999 has 5 whorls, and measures : Height, 

 14 mm ; greater diameter, 28.7 mm ; lesser diameter, 22.2 mm. It was 

 collected by F. Juan at Novaliches, Rizal Province, Luzon. 



Additional material. — Thirteen topotypes are before me, six of 

 which are U.S.N.M. No. 313000; the other seven will be returned 

 to the Philippine Bureau of Science. These specimens yield the 

 following measurements : 



OBBA MARMORATA ILINENSIS, new subspecies 



Plate 86, Figure 3 



This is the smallest race of this species. Its distribution is rather 

 interesting, and it is quite possible that careful collection in Mindoro 

 will show races of it eventually. It is a pale race, the shell being 

 rather broadly conic. The periphery of the last whorl is rather 

 rounded than angulated, but an obsolete indication of angulation is 

 present. The incremental lines on the upper and lower surface are 

 not so rough as in the other races, and the wrinkling of both surfaces 

 resembles scratches more than the strong wrinkles of some of its 

 other subspecies. The aperture is oval, and moderately broad, and 

 the peristome is strongly expanded and reflected on the outer and 

 basal lips. The umbilicus is narrow and half covered by the re- 

 flection of the inner lip. 



