16 THE NAUTILUS. 



more depressed and of much darker coloration. The basal 

 portion of the last whorl is also less inflated. The aperture is 

 proportionately longer and more compressed. The type, Cat. 

 No. 218765, U. S. N. M., has 4.4 whorls and measures: alti- 

 tude, 23 mm. ; greater diameter, 50.2 mm. ; lesser diameter, 

 38.5 mm. 



OBBA LISTERI BATANENSIS, new subspecies. 



The Obba from the island of Batan, is also distinct from 

 any of the other forms known from the Philippines, as shown 

 by specimens received from Mr. Webb. It belongs to the Obba 

 listen complex. It is nearest related to Obba listeri costata 

 Semper, from the island of Camigin, of the Babuyan Group, 

 north of Luzon. It differs from this markedly by its more 

 regularly conic outline, somewhat greater elevation, paler 

 ground color, and rougher incremental sculpture. The type, 

 Cat. No. 218764, U. S. N. M., has 4.4 whorls and measures: 

 altitude, 10 mm. ; greater diameter, 26.7 mm. ; lesser diam- 

 eter, 22.1 mm. 



COCHLOSTYLA POLYCHROA BURIASENSIS, new subspecies. 



Specimens of the Cochlostyla polychroa complex sent to the 

 U. S. National Museum for determination have made it neces- 

 sary to critically examine that group. This examination has 

 revealed the fact that most of the specimens in collections 

 passing under this name are from the island of Burias. The 

 type locality for Cochlostyla polychroa is Temple Island, an 

 island adjacent to Burias. A series of specimens from this 

 island in the collection of the National Museum show that the 

 shells of the typical form, that is Cochlostyla polychroa poly- 

 chroa, are larger, decidedly more elevated and conic than the 

 specimens from the island of Burias. The coloration, too, is 

 much more vivid in the Burias shells than those from Temple 

 Island. I shall therefore bestow the name Cochlostyla poly- 

 chroa buriasensis upon the shells from Burias Island. 



The type of this shell, Cat. No. 218788, U. S. N. M., has 4.7 

 whorls and measures : altitude, 35 mm. ; greater diameter, 

 30.7 mm. 



