ART. 5 LUZON LAND SHELLS BAETSCH 3 



A KEY TO DIFFERENTIATE SPECIES OF COCHLOSTYLA 



Hydrophanous lines and bands present. 



Strongly incised spiral lines present on spire and base dubiosa. 



Strongly incised spiral lines absent on spire and base submirabilis. 



Hydrophanous lines and bands absent. 



Periostracum strongly develoi>ed persimilis. 



Periostracum almost absent mirabilis. 



Of C ochlostyla dubiosa Pfeifi'er three races, which I shall recog- 

 nize subspecifically, are in the collection of the United States 

 National Museum. The typical race comes from the island of 

 Samar, another from the small island of Capul off the northwest 

 coast of Samar^ which I shall call Cochlostyla dubiosa capulensis, 

 and the third Cochlostyla dubiosa volubilis Reeve from the island 

 Batan, of the Batanes Group, the northernmost of the Philippine 

 Islands. 



This discontinuous distribution, presented by the last mentioned 

 race, has puzzled all the writers who have given serious thought to the 

 problem. Von Mollendorff has suggested introduction with plants. 

 This seems not unlikely since Batan Island was given considerable 

 prominence during Spanish occupation. The fact that the other 

 islands of the Batanes Group have not yielded the same or allied 

 races adds additional color to this contention. The Batan shells 

 differ sufficiently from those of Samar and Capul to deserve a name. 

 It would be interesting to know from where they came originallj^, 

 in order to determine whether the characters which they present are 

 still the same as those of the ancestral stock or whether they are the 

 responses to the more northern environmental conditions. 



The following brief description and figures should help to 

 recognize these races : 



COCHLOSTYLA DUBIOSA DUBIOSA Pfeiffer 



Plate 1, Figures 1-4. 



1842. Helix decipiens Reeve, Concb. syst,, vol. 2, pi. 165, fig. 16 (not pi. 163, 



fig. 3). 

 1842. Helix duhiosa Pfeiffeb, Symbolae II, p. 71. 



1845. Helix dubiosa Pfeiffer, Proc. Zool. Soc. London, pp. 123-^. 



1846. Helix dubiosa Pfeiffek, Martini-Chemnitz, Conch. Cab., ed. 2, vol 1, 



part 12, p. 281 in part, exclusive of figures. 

 1848. Helix dubiosa Pfeiffer, Monogr. Helic. vivent., vol. 1, p. 252 in part. 



1850. Helix dubiosa Axbers, Heliceen, ed. 1, p. 105. 



1851. Helix dubiosa Reeve, Conch. Icon., pi. 5, fig. 22. 



1853. Helix dubiosa Pfeiffer, Mon. Helic. vivent., vol. 3, p. 188, in part. 

 1853. Helix dubiosa Pfeiffer, Mon. Helic. vivent., vol. 3, p. 172, in part. 



1858. Helix dubiosa H. and A. Adams, Gen. Rec. MoL, vol. 2, p. 192. 



1859. Helix dubiosa Pfeiffer, Mon. Helic. vivent., vol. 4, p. 210, in part. 



m. 



