44 HELIX C6RYDA. 



or pale purplish above, and encircled by several narrow, continuous 

 or interrupted dark bands. It is generally thinner and more de- 

 pressed than the preceding forms, and is perhaps the most abund- 

 ant of all the color mutations, (figs. 21-25, 31). H. hebe (figs. 

 35-37) is the same. 



( 4.) Conical ; dark chestnut or reddish brown all over, uni- 

 colored or with uarrow } oblique white lines, which are close, crowded 

 ( fig. 32 ) or more separated ( figs. 33, 34 ). This is H. strobilus 

 PER. (figs. 26-28.) 



H. DENNISONI Pfeiffer. PL 14, figs. 86-88. 



Verv similar to color-mutation no. 3 of H. alauda, but distin- 



tt 



guished by the deep narrow color of the parietal Avail and inside of 

 the aperture. Coloration consisting of narrow, oblique deep-brown 

 and yellowish lines on a white ground; with or without indications 



of two spiral interrupted bands. 



Alt. 15 diam. 19 ; alt. 12 diam. 16 mill. 



Cape St. Cruz, S. E. Cuba. 



H. dennisoni PER. Zeitschr. f. Mai. 1853, p. 56 ; Moongr. iii, p. 

 645 ; Nowt. Conch, i, p. 53, t. 15, f. 7-10. REEVE, f. 1020. IT. 

 Juliana POEY, Memorias, i, p. 208, t. 25, f. 13-16. 



I have seen numerous specimens of this form, all from the locality 

 given above. There are also before me specimens having the col- 

 oration of fig. 31, of pi. 16, but agreeing with dennisoni in the dark 

 parietal wall. Two of these are figured on pi. 32, figs. 41-44. It 

 may be noted that no true alauda, with light parietal wall are in the 

 collection of the Academy from Cabo St. Cruz. My figures on pi. 

 14 are too red. 



H. OVUMREGULI Lea. PI. 14, figs. 89-91. 



Imperforate, depressed, solid, opaque, polished all over, scarcely 

 striate, white or tinted with bluish, creamy or pink, more or less 

 thickly covered witd dark dots scattered irregularly, and with or 

 without numerous narrow brown spiral bands; spire depressed, a 

 little convex, apex obtuse; whorls 4g, scarcely convex, the last 

 wide, rounded at the periphery, depressed, very suddenly and very 

 deeply deflexcd anteriorly ; aperture sub-horizontal, oblong, dark 

 within ; peristome expanded, labiate; white or ( rarely) deep chest- 

 nut brown, its margins sub-parallel or converging, the upper arcu- 

 ate, lower straight and thickened by a callus inside. 



Alt. 10-12, diam. 17-20 mill. Guantanamo etc., Eastern Cuba. 



