bartsch: classification of helicinidae 653 



breaks up into a number of geographic races. Geophorus trochaceus 

 trochaceus jNIollendorff comes from the island of Leyte. It is a very 

 small shell of elongate conic form, having the peripheral keel rather 

 rounded and the upper surface finely granulate. A specimen of Geo- 

 phorus trochaceus trochaceus Mollendorff from Leyte, Cat. No. 302767, 

 has 5.3 whorls and measures: altitude, 5.3 mm.; greater diameter, 6.8 

 mm. The most northern race, Geophorus trochaceus calayanensis 

 n. subsp., comes from Calayan Island, of the Babuyanes group. This 

 is considerably larger than the typical form with coarser incremental 

 lines and granulations. The peripheral keel, too, is stronger, irregular 

 and wavy. The type of this, Cat. No. 334254, has 5.3 whorls and 

 measures: altitude, 6.2 mm.; greater diameter, 8.1 mm. 



Another, Geophorus trochaceus palauiensis n. subsp., recalls strongly 

 the shell from Calayan. It is almost of the same size but has the pe- 

 ripheral keel well rounded and is in every way less coarsely sculptured 

 than the northern representative. It comes from Palaui Island. The 

 type. Cat. No. 258789 has 5.3 whorls and measures: altitude, 6.2 mm.; 

 greater diameter, 8.9 mm. 



Two additional subspecies occur upon the island of Luzon. One, a 

 medium sized form, Geophorus trochaceus marivelesanus n. subsp., which 

 is known from the southern end of the Zambales range at Mariveles. 

 This, like the Palaui race, has the upper surface coarsely granular, but 

 it is much smaller. The type. Cat. No. 302774, has 5.3 whorls and 

 measures: altitude, 5.3 mm.; greater diameter, 7.8 mm. 



The smallest race, Geophorus trochaceus nanus (Mollendorff) Wagner, 

 comes from Sibul, Bulacan Province. This race has a lesser number of 

 whorls and is a little more finely granular than the other Luzon forms. 

 A typical specimen, Cat. No. 195491, having 4.5 whorls measures: ali- 

 tude, 4 mm.; greater diameter, 5.8 mm. 



Section IV 



Shell banded acutissimus Sowerby 



Shell not banded. 



Shell broadly conic palananus Bartsch 



Shell narrowly conic. 



Operculum with a knob at the posterior columellar border 



perezi Bartsch 

 Operculum without a knob at the posterior columellar border 



caramoanus Bartsch 



The section in which the spiral sculpture is absent and in which the 

 columella is not excavated and in which there is no decided angle at 



