CERION, GROUP XI. 261 



others show some obscure bluish stains, besides the usual basal girdle, 

 which may be either distinct or wanting in this and the allied species. 

 Kuster's figure shows about 28 ribs on the penultimate whorl. 

 Pfeiffer gives alt. 24, diam. 10, apert. 9 mill, long, 8 wide above as 

 the dimensions, Kiister's types being apparently the only specimens 

 then known to him. 



Forms from Andros (Subsp. GRISEUM Mayn.). 



A knowledge of the Cerions of Andros we owe to Mr. C. J. May- 

 nard, who explored various keys and mainland localities in the neigh- 

 borhood of Middle Bight, on the eastern side. In general the blue- 

 white color differentiates them from New Providence forms, but in 

 many colonies mottled specimens occur, indistinguishable from some 

 of the New Providence shells. 



Form griseum Mayn. (pi. 43, figs. 57, 58). Intervals in part 

 dull purple-fleshy or purplish-brown, the ribs white, base violet or 

 flesh-colored in front. Ribs numerous, 27-28 on penult, whorl. 

 Aperture brown inside, the lip reflexed and recurved, built far for- 

 ward of the reflection, beveled (fig. 57). Parietal callus a strong, 

 narrow ridge; parietal tooth stout. Length 25-26, diam. 11^-11 

 mill. Fields north of Fresh Creek, about a mile from the settle- 

 ment, along the road to Calabash Bay ; also south of the creek, 

 where it " completely intergrades " with the following. In fields 

 directly south of the little settlement on Fresh Creek, but on the 

 opposite side of the creek, is found the form called S. glans by May- 

 nard (not glans Kiister). It is white or bluish-white, often with 

 some livid stains; rather short; 26-28 riblets on penult, whorl; 

 interior dark, dull brown. The peristome has a more or less devel- 

 oped flange. Length 22, diam. 10.8 mill. Sometimes it is smaller, 

 20^x9 mill., with the lip but little thickened, and sometimes larger, 

 28^x11 mill., with fewer riblets, 23 on the penult, whorl (pi. 43, 

 fig. 53 ; " form no. 2," fig. 54 ; " form no. 3," figs. 55, 56. Some 

 shells are copiously mottled, and the larger examples of this form 

 and of griseum can be exactly matched among New Providence 

 specimens of the " agava " form. 



Form regulum Maynard (pi. 43, fig. 59) is very large, 37^x15 

 mill., or sometimes as short as 29 mill. ; the ribs are very numerous 

 and regular, 34 on the penult, whorl ; blue-stained white, the inte- 

 rior dark brown, parietal ridge strong. Only shells inhabited by 



