LAND SHELLS OF GENUS OBBA FROM MINDORO 



365 



of the last whorl. The base is flesh-colored with an interrupted 

 brown band one-third of the way between the summit and the suture 

 anterior to the summit. The peristome is flesh-colored, while the 

 inside of the outer lip is a purplish brown. The nuclear whorls have 

 the usual fine incremental lines and spiral striations. The post- 

 nuclear whorls are strongly malleated on the anterior two-thirds of 

 the turns on all but the last third of the last whorl. The postnuclear 

 whorls are also marked on the upper surface by rather rough incre- 

 mental lines and moderately strong incised spiral striations, those on 

 the basal portion being a little more pronounced than those on the 

 spire. Aperture broadly oval; peristome thickened and reflected, 

 covering half of the umbilicus at the parietal wall. There is a strong 

 tooth on the median portion of the inner lip. 



Type.— The type, U.S.N.M. No. 382708, comes from the Quadras 

 collection and was collected at Sitio Panlanau, Bongabon, Mindoro. 

 It has 4.6 whorls, and measures: Height, 13.6 mm; greater diameter, 

 30.6 mm; lesser diameter, 24.4 mm. 



Remarks. — Three additional specimens, U.S.N.M. No. 239845, 

 were collected by Mr. Schultze at Bongabon. These yield the follow- 

 ing data: 



This subspecies in the character of malleations resembles Obba 

 planulata paluana, from which it is at once distinguished by its much 

 larger size and flatter form and less strong spiral sculpture. In its flat 

 shape and angulated periphery of the early whorls it suggests O. p. 

 varaderoana, from which its smaller size and less conspicuous spiral 

 sculpture, as well as the less malleated base, distinguish it. 



OBBA PLANULATA PALUANA, new subspecies 



Plate 93, Figure 1 



The shell is depressed-helicoid with the periphery of the last whorl 

 well rounded. The first nuclear whorl is flesh-colored, the succeeding 

 turns pale brown. The postnuclear whorls are of flesh-colored 

 ground color, spotted, streaked, and vermiculated with bright chest- 

 nut-brown. The last whorl is a little paler than the rest. A narrow 

 median brown band encircles all the postnuclear whorls except the 

 last fourth of the last turn. The base is flesh-colored, the vermicula- 

 tions extending to the faint brown spiral line, which is at about one- 

 third of the distance between the periphery and the umbilicus, anterior 



