382 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



Spirals continue to the aperture; the color of the last whorl 

 dirty white, the earlier whorls dull flesh color, the apex usu- 

 ally pale, and in rare instances a pale peripheral band is pres- 

 ent; umbilical perforation minute; aperture with a thickened 

 not reflected, continuous margin, the pillar and body as well 

 as the outer lip without projecting callosities ; the axis very 

 slender and distinctly twisted, probably not tubular. Length 

 of shell 15.5 ; of last whorl 9.0 ; of aperture 5.5 ; 

 diameter 7.0 mm. 



Obtained by Mr. Ochsner in "a fairly dry" region on Jer- 

 vis (or Rabida) Island, at an altitude of 900 to 1000 feet. 



14. Helicina (Idesa) ochsneri, new species 

 Shell much resembling H. nesiotica in a general way but 

 higher, more conical and slightly larger; while nesiotica has 

 a thin smooth periostracum and the specimens are clean when 

 living, the present species has a blackish periostracum which 

 is raised on the spire between the sutures into two or three 

 fringed short spiral threads. The periostracum appears to 

 be of an adhesive nature and all the specimens in their origi- 

 nal condition are more or less covered with a blackish coat- 

 ing. When this is cleaned off the underlying shell has much 

 the coloration and surface of nesiotica. Maximum diameter 

 of shell 4.7 ; height 3.5 mm. 



Albemarle Island, eight miles west of Turtle Cove, near 

 salt lagoon; and at Cowley Mountain on moist ground, 350 

 to 500 feet above the sea; Ochsner. 



15. Williamia galapagana Dall. 



Shell small, ovate, conical, the apex curved forward and 

 situated at about the anterior third of the length; surface 

 probably with a thin periostracum when fresh, but in all spec- 

 imens seen this has been lost and the surface is brilliantly 

 polished ; the color is of a rosy brown with numerous paler 

 radial streaks; margin simple, often slightly irregular from 

 adapting itself to the sustaining surface; muscular scar in- 

 terrupted as usual in the family. Length 9.0 ; height 

 3.5 ; breadth 7.0 mm. 



Station on floating seaweed at the Galapagos Islands; 

 specimens collected on the beach at Hood and Chatham 

 Islands. 



