118 



Cincinnati Society of Natural History. 



DESCRIPTION OF A NEW SPECIES OF BOURGUETI- 



C BIN US. 

 B} r P. DeLoriol, of Switzerland.* 



BOURGUETICRINUS ALABAMENSIS, D. Sp. 

 Plate V., fig. 1, magnified 5 diameters ; la & lb, magnified 6 diameters ; le, natural size. 



This species is as yet known only by the basal cone which supports 

 the calyx, and which is composed of several enlarging segments of the 

 column surmounted by the basal plates. The height of the inverted 

 cone is 5 mm.; the diameter of the basal plate is 3^ mm.; and that of 

 the inferior segment of the column is 3 mm. in its major axis. Its 

 form is faintly swollen in the middle; the surface is smooth. The 

 sutures are very indistinct, and it is a difficult matter to determine 

 what was the height of the basal plate. The superior face of the cone 

 carries five slender, and comparatively elevated radiating ridges, 

 which bound five deep depressions in which the basal pieces of the 

 catyx were lodged; in the center an enlargement of the central canal 

 constitutes the bottom of the calyx cavit5. The articular face of the 

 lower joint of the column forming the inferior end of the cone, is 

 elliptical, but the length of its major axis does not, however, much 

 exceed that of its minor axis. It is slightly concave, and encircled by 

 a feeble rim along the circumference line; the transverse articular ridge 

 process is reduced to two elongated tubercles, which proceed from the 

 marginal rim. Central canal comparatively large. 



Relations and Differences. — Although this species is still very 

 imperfectly known, one can affirm that it is certainly distinct from 

 the Bourgueticrinus ellipticus, Miller, by the much less swollen form 

 of the basal cone, which is but slightly convex in outline; and by the 

 facts, that the lower segment of the cone is already elliptical, and 

 already possesses the rudiments of a transverse articular ridge. 

 Furthermore, the radiating carinse are very much more salient, and 

 consequently the depressions which they separate, very much deeper. 

 Fin alh', by its central canal being relatively much larger. 



Locality: Livingston, Alabama, Ripley Group, of the Cretaceous 

 or at the top of the Rotten Limestone. 



Collected by S. A. Miller. 



* The description is translated from the French MS. of the author, which may account 

 for any imperfections found in it.— [Ed.] 



