178 BULLINA-OVULACT^ON. 



Of the two specimens (types) in the British Museum, one is with- 

 out the bands. The columella is obliquely truncated. This species 

 differs from the preceding in being very pellucid, in the gray, not 

 red color of the spiral bands, and the absence of longitudinal wavy 

 lines. 



B. DESHAYESii Pilsbry. PI. 45, figs. 27, 28. 



Shell ovate-turgid, thin pellucid ; apex obtuse, white ; encircled 

 by two narrow, distant black lines. Spire short, obtuse. Whorls 5, 

 narrow, convex, separated by a subcanaliculate depressed suture ; 

 last whorl large, obtuse with base transversely delicately sulcate. 

 Aperture ovate-elongate, narrow and subemarginate behind, colum- 

 ella cylindrical, narrow, straight. Alt. 15, diam. 10 mill. (Dh.). 



Island of Reunion (Dh.). 



Bulla vitrea Pease, Deshayes, Moll. Reun., p. 56, pi. 8, f. 2, 3. — 

 Bullina vitrea ISIartens in Mobius' lieise n. Mauritius, p. 304. 



This species differs from B. vitrea Pse. in the non-truncated colum- 

 ella and more obese form. The shell is thin, semi-transparent, 

 milk-white, with two lines of intense black-brown. The suture is 

 deep and somewhat channelled ; last whorl five-sixths the entire 

 length of the shell. Entire surface sculptured with fine, equal, 

 shallow spiral grooves, in the bottoms of which a lens shows a regu- 

 lar punctation like that of Ada^on. The outer lip is arched forward, 

 forming a sort of shallow sinus behind. 



Genus OVUL ACTION Dall, 1889. 



Ovulaetceon Dall, Blake Gastropoda, Bull. M. C. Z., xviii, p. 42. 



Shell cyprseiform, involute, with an apical perforation, as in 

 Bulla; columella simple, without jDlaits; margin of the aperture 

 continuous, simple, thickened, the callus on the body elevated, 

 parallel with the outer lip ; aperture narrow, almost linear, slightly 

 effuse at the extremities, as long as the shell. Type 0. Meekii Dall. 



This interesting form resembles an involute Globiconcha with 

 perforate apex and thickened aperture, or a rounded Adceonella 

 without plaits. In the unplicate series of the Adceonidce it holds a 

 place analogous to that of Cyproiadceon White among the plicate 

 forms. (Dall). 



O. MEEKII Dall. PI. 49, figs. 20, 21. 



Shell with the outline of a small Cyproea, like C. edentula, widest 

 in its posterior third, white, polished with fine, distinct, im- 



