2 PEOCEEDIN'GS OF THE NATIONAL MUSEUM vol.78 



shell figured by Mr. Reeve under the name H. decipiens^ Sowerby ^ 

 and this figure quite well represents what I consider CocMostyla 

 duhlosa. It was more than likely based upon one of Cuming's shells 

 from the island of Samar. Pfeiffer also says that his species was 

 " Collected by Mr. Cuming on the island of Samar." 



A year later Pfeiffer redescribes and figures Helix duhiosa in the 

 Conchylien Cabinet of Martini and Chemnitz (p. 281, pi. 46, figs. 5 

 and 6). The description is a copy of his former definition, but 

 the figure represents one of the races of what I am here calling 

 Cochlostyla submirabilis Mollendorff. This was the beginning of 

 the confusion that has since prevailed. 



Cochlostyla duhiosa Pfeiffer closely resembles Cochlostyla sub- 

 Tnirahilis both in shape and color markings. Both may or may not 

 have a dark umbilical area and one to three brown spiral zones. 

 In all our Cochlostyla duhiosa the brown zones are never peripheral 

 but, when present, sub or supraperipheral, always leave a light 

 zone at the periphery. In Cochlostyla suhmirahilis on the other 

 hand, if a dark zone is present on or near the middle of the whorl 

 it always occupies the peripheral area. Both species have hydro- 

 phanous spiral lines or bands of varying width. The most signifi- 

 cant distinguishing character however is the presence of very regular 

 closely spaced strongly incised spiral lines in Cochlostyla duhiosa. 

 These lines are present both on the areas occupied by the hydro- 

 phanous bands and the spaces between them, on spire and base. 

 In Cochlostyla suhinirahilis Mollendorff incised spiral lines, if present 

 at all, are merely indicated and never regularly developed, nor do 

 they cover the entire surface of the shell. This species also has a 

 tendency to be provided with crisscross scratchy lines. 



Two other species with which some races of both of these species 

 have been confused are Cochlostyla inirahilis Ferussac and Coch- 

 lostyla persimilis Ferussac. The races of these while in some 

 instances approximating Cochlostyla suhmirahilis Mollendorff can be 

 easily distinguished from them by the absence of the hydrophanous 

 spiral zones. In Cochlostyla inirahilis there is scarcely any perios- 

 tracum, the shells usually being of white ground color. In Cochlo- 

 styla persiinilis, on the other hand, there is always a strongly de- 

 veloped straw-colored, pale orange or brownish orange periostracum 

 present. 



Cochlostyla speciosa Jay has been referred to C. duhiosa by some 

 authors. Through the kindness of the American Museum of Natural 

 History I have been able to examine the two fine specimens upon 

 which Jay based his name. They do not belong here but are allied 

 to Cochlostyla coccomelos Sowerby. 



1 Conchologia Systematica, vol. 2, pi. 145, fig. 16. 



