Geological Papers. 215 



Volvaria alba Brown, Illustr. Conch. G. B., p. 3, pi. XIX, figs. 43, 44. 



Cylichna alba (Brown) Loven, Ofversight K. Vet.-Akad, Forth., 1846, p. 

 242. Tryon, Man. Conch., vol. XV, p. 290, pi. LX, fig. 16, 1893.'" Ar- 

 nold, Mem. Cal. Acad. Sci., vol. Ill, p. 192, pi. X, fig. 18. 



"Shell small, cylindrical, smooth; spire truncated; aperture nar- 

 row posteriorly for about two-thirds length of shell, when the inner 

 lip gradually retracts to the columella, forming a rounded anterior 

 end to aperture; columella callous, with one plait." '^''^ 



Only a broken specimen of this species was obtained from the 

 Pliocene of the Quillayute formation. 



Living: San Diego to Monterey, Cal. (Cooper). 



Pleistocene: San Diego, Ventura, San Pedro (Arnold): San 

 Diego, Santa Barbara, Cal. (Cooper). 



Pliocene: San Diego well (Cooper); Quillayute, Wash. (Reagan). 



Superorder Streptoneura ; Order Ctenobranchiata. 

 Superfamily Toxoglossa; Family LII Pleurotomid^. 

 Genus Pleurotoma Lamarck. 



" Shell turriculated, fusiform, terminated anteriorly by a straight, 



more or less long canal ; aperture oval ; columellar lip smooth, 



straight or sinuous ; outer lip somewhat sinuous, with a posterior 



sinus. Pleurotoma babylonia Lam. is a characteristic species." 



(Arnold). 



48. Pleurotoma perversa. Plate V, fig. 48. 



Pleurotoma perversa Gabb.. Proc. Cal. Acad. Sci., vol. Ill, 1865, p. 183; 

 Pal. Cal., vol. II, pp. 6, 73, pi. I, fig. 10, 1869. Cooper, 7th Ann. Kept. 

 Cal. St. Min., 1888, p. 260; equals Surcula perversa Gabb, Tryon, Man. 

 Conch., vol. VI, p. 239, pi. VI, fig. 79, 1884. Arnold, Mem. Cal. Acad. 

 Sci., vol. Ill, p. 200, 1903. 



Shell small, sinstral, elongate, slender ; whorls eight to twelve ; 

 .-pire high ; spire in specimens at hand bent a little near apex ; 

 suture deep ; body whorl, including canal, nearly half of the entire 

 length of the shell ; aperture, except lower end of canal, not seen ; 

 canal extended ; surface smooth except for fine incremental, some- 

 what wavy lines, which are now mostly weathered away. 



Dimensions: Axial length, 37; lat. of body whorl, 11; length 

 of body whorl, 21. 



Only a few specimens were obtained from the Quillayute forma- 

 tion. 



Living : Catalina Island, Cal., to Vancouver Island (Cooper). 



Pleistocene : San Pedro to Santa Barbara (Cooper); San Pedro 

 ( Arnold ) . 



Pliocene : San Pedro, Cal. ; mouth of Quinaielt river, near Grand- 

 ville, Wash, (Arnold); Quillayute, Wash. (Reagan). 



61. After Arnold, loc. cit. 



