DSC. 19, 1921 bartsch: key to Philippine operculate mollusks 503 



302763, U. S. N. M., comes from Cagayan, Mindanao. It has 4.5 

 whorls and measures: altitude, 7.5 mm. ; diameter, 13.5 mm. 



Two forms of Ceratopoma are known from the island of Leyte, one 

 having the umbilical callus about half the diameter of the shell, which 

 is Ceratopoma emaculaia MoUendorff, the other having the umbilical 

 callus only about one-fourth the diameter of the shell, which may 

 be known as Ceratopoma emaculata cabaliana, subsp. nov. The 

 former we collected in the mountains south of Tacloban, Cat. No. 

 258771, U. S. N. M. The latter comes from Sitio Menoiho, Caba- 

 lian, Leyte. The type is Cat. No. 302741, U. S. N. M. 



The remaining members of the genus are all from the island of 

 Luzon, and are small, none exceeding 8 mm. in diameter. Two of 

 these have a subglobose outline, namely, Ceratopoma quadrasi Mol- 

 lendorff, which comes from Caxiguran, and the shell described by 

 Wagner as Ceratopoma contermina camiguinensis from Camiguin, 

 Luzon. The latter I have not seen, and consequently have not placed 

 in the key. The figure given by Wagner resembles that of Cerato- 

 poma quadrasi, but from what we know of the distribution of Heli- 

 cinas there seems little doubt that it is distinct, and if specimens 

 were at hand characters could be given to key it. 



The remaining forms are depressed-conic, and can be divided into 

 two species, one having the upper surface strongly spirally striated. 

 This is Ceratopoma contermina (Semper) Kobelt, which was described 

 from Pancian, northern Luzon, and has a diameter of more than 6 

 mm., and a smaller race, which may be called Ceratopoma contermina 

 iota, subsp. nov., from Cagayan, Luzon. The type of this, Cat. 

 No. 302758, has 4 Vs whorls and measures: altitude, 3.2 mm. ; greater 

 diameter, 5.6 mm. The other species, Ceratopoma rosaliae Pfeififer, 

 is without spiral striation on the upper surface. The typical form 

 we have seen from the eastern side of Isabella and Nueva Viscaya 

 Provinces, Luzon. 



A smaller race occupies the Manila Bay region, to which we now 

 give the name Ceratopoma rosaliae manilana, subsp. nov.. The 

 type, Cat. No. 184924, U. S. N. M., comes from Manila. It has 

 4V3 postnuclear whorls and measures: altitude, 3.8 mm.; diameter 

 6.7 mm. 



A still smaller race comes from the Benguet Province which we have 

 called Ceratopoma rosaliae igorota, supsb. nov., the type of which 

 has 4V4 whorls and measures: altitude, 3.2 mm., diameter, 5.7 mm. 



