348 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



This subspecies resembles most nearly Obba listeri mayabigana from 

 Mindoro, from which it differs in being much more elevated and in 

 having the malleations on the base extending far nearer the umbilicus. 

 0. I. mayabigana also has a decided, fine, crisscross sculpture, which 

 appears to be absent in the present race. 



OBBA LISTER! KALCONA, new subspecies 



Plate 88, Figure 3 



The shell is decidedly depressed-lenticular with a very acute pe- 

 ripheral keel and a broad, open umbilicus. The nuclear whorls are 

 flesh-colored; the postnuclear whorls are decidedly mottled, spotted, 

 and streaked with flesh color, pale brown, darker brown, orange, and 

 variations of these elements. A supramedian brown band encircles 

 the whorls on the upper surface. The base is rather inflated, yellowish 

 buff with a broad bright chestnut-colored band, which is a little 

 posterior to the middle between the periphery and the umbilicus. The 

 peristome is white with a buffish tinge. The inside of the outer lip is 

 very pale brown. The first postnuclear whorl is marked by incremen- 

 tal lines and rather weak spiral striations; the remaining turns are 

 malleated, a little less strongly near the summit than the periphery. 

 They are also marked by strong incremental lines and rather feebly 

 incised spiral lines. The base slopes from near the umbilicus to the 

 acute periphery and is malleated to the edge of the umbilicus, the 

 malleations being stronger toward the periphery. It is also marked 

 by incremental lines and fine spiral striations. The latter are best 

 expressed about the umbilical area. Aperture somewhat polygonal, 

 very broad, with a decided dent at the peripheral angle. Peristome 

 thickened and reflected, covering about one-fourth of the umbilicus. 

 The inner lip with a conspicuous tooth on its middle. 



Type.— The type, U.S.N.M. No. 382929, was collected by Col. 

 Edgar A. Mearns on Mount Halcon during his expedition to that 

 mountain in Mindoro. It has 4 whorls, and measures: Height, 9.9 

 mm; greater diameter, 27.4 mm; lesser diameter, 22.8 mm. 



Remarks. — There are two additional fragments obtained on the 

 same expedition in our collection. They are registered as U.S.N.M. 

 Nos. 256542 and 256503. 



This subspecies differs from all the other members of the region by 

 its depressed-lenticular form and the width of its umbilicus. 



OBBA LISTERI MINOR (Mollendorff) 



Plate 89, Figure 2 



1898. Obbina listeri minor Mollendorff, nom. nud., Abh. Naturf. Ges. Gorlitz, 



vol. 22, p. 86, in part. 

 1905. Obbina listeri minor Mollendorff, Kobelt, and Winter, Semper's 



Reisen im Archipel der Philippinen, vol. 10, pt. 1, p. 22, in part, pi. 6, 



fig. 2. 



