292 CYLICHNA. 



Aperture narrow above, dilated below; columella short, arcuate; 

 lip acute, projecting a little above the vertex, expanded toward the 

 base. Color whitish, hyaline, under a brown epidermis. (Dautz.^). 



Dakar, W. Africa. 



CylicJma grimaldii DAUTZ., Mem. Soc. Zool. France iv, p. 26, pi. 

 3,f. 1,1891. 



Compared with 0. alba, this species is of larger size, less elongated 

 form and thinner shell. The spiral strise, which are effaced in 

 the middle of C. alba, are more strongly marked, and cover the 

 whole surface. It is larger than C. propinqua Sars, more cylin- 

 drical, less globose, with shorter, more arcuate columella, thinner 

 shell and more distinct stride. 



C. OCCULTA Mighels. PL 28, figs. 35, 36, 37, 38, 39, 40, 41. 



Shell solid, white, covered with a very thin whitish yellow epider- 

 mis ; ovate, rather short and swollen, the diameter about two-thirds 

 the altitude. Vertex obtusely truncated, slightly concave in the 

 middle ; base rounded ; aperture not very narrow, dilated below, 

 the outer lip projecting above the crown of the shell, a little arcuate 

 and inflexed in the middle ; columella nearly straight, with a broad 

 fold. Surface smooth, polished, shining, but covered with many 

 impressed, subundulating lines, which are quite conspicuous. Alt. 

 9 mill. Radula with the formula 2,1.1.1,2. (Sars, C. propinqua). 

 Norway, Spltzbergen and Greenland, south to Maine. 



Bulla striata BROWN, Illustr. Conch. G. B., pi. 38, f. 41, 42 ; 1827. 

 Second edit., p. 57, pi. 19, f. 41, 42. Cylichna striata JEFFREYS, 

 Ann. Mag. N. H. (4), xx, p. 492. SMITH, t. c., p. 140. Not Bulla 

 atriata Brug. Bulla occulta MIGHELS, Proc. Bost. Soc. N. H. i, p. 

 50, 1841 ; Bost. Journ. N. H. iv, p. 54, pi. 4, f. 11. OLD., Invert. 

 Mass. (edit. W. G. B.), p. 223. KRAUSE, Zool. Jahrbiicher, vi, p. 

 363. Bulla reinhardi Holb., MOLLER, Index, Moll. Groenl. p. 6, 

 1842. Cylichna reinhardi LECHE, K. Sv. Vet.-Akak. Handl. 

 1878, p. 72, pi. 1, f. 21. AURIVILLIUS, Vega-Exped. iv, p. 370. 

 Bulla scalpta REEVE, in The Last of the Arctic Voyages (Belcher's), 

 ii, p. 392, pi. 32, f. 3 (bad). cf. Cylichna scalpta LECHE, t. c., p. 73, 

 pi. 1, f. 22. -Bulla propinqua M. Sars, 1858, G. O. SARS, Moll. Reg. 

 Arct. Norv., p. 284, pi. 18, f. 5. 



This species is distinguished by its rather inflated form and 

 obvious spiral striation. Jeffreys and others have called it C. striata 



