296 PROCEEDINGS OF THE ACADEMY OF [Nov., 



MARINE MOLLUSKS OF HAWAII, Vni-XIII. 

 BY HENRY A. PILSBRY. 



The description of material submitted to me for determination 

 by Mr. D. Thaanum, Prof. Wm. A. Bryan and Mr. J. M. Oster- 

 gaard, with other forms collected by myself in 1913, is here con- 

 tinued. Former papers of this series were published in these Pro- 

 ceedings for 1917, pp. 207-230, and 309-333 (1918). 



VIII. Stylifer, Odostomia, Acteocina 



One Hawaiian species, Stylifer rohusfus, was described by Mr. 

 Pease. The Hawaiian species referred to Scalenostoma apiculatuni 

 Souv. in a former paper' is perhaps a Stylifer or closely related 

 thereto. It is parasitic or commensal on Echinoderms. Whether it 

 is without an operculum, like the typical Stylifers, has not been noted. 



Stylifer deformis Pease, from the Paumotus, resembles both of the 

 Hawaiian forms from the Bryan collection, without exactly matching 

 them. A series of four S. de/ormis, including the figured type, is in the 

 collection of the Academy. They show considerable variation in 

 the degree and direction of curvature of the acuminate early whorls. 



Stylifer deformis hawaiensis n. subsp. Fig. la. 



Honolulu Harbor, Oahu, collected by W. A. and E. J. Bryan. 



The shell is thin, white. The upper fourth is acuminate, of 

 about eight nearly flat, smooth whorls. The rest of the shell, about 

 63^2 whorls, tapers more rapidly; the whorls increase slowly and 

 almost regularly, and are rather" strongly convex; and the surface 

 is malleate, having many spiral facets, giving some appearance of 

 having coarse, low, spiral threads on the last two whorls. The last 

 whorl is well rounded basally. The aperture is ovate. Columella 

 is slightly concave. 



Length 9.2, diameter 3.2 mm. 



iProc. A. N. S., Phila., 1917, p. 226. 



