182 TORNATINA. 



Tornatina differs from Retusa in the conspicuously channelled 

 suture and the peculiar, projecting apex; but it has been united 

 with that group by some authors, and until the soft parts are known, 

 the exact status of the group is a mere matter of opinion. We pre- 

 fer not to assume, with Fischer, that in anatomy it is like "Coleo- 

 physis," although that is not in the least improbable; for that 

 assumption would force us to disturb the received nomenclature to a 

 radical degree ; and it is always better to continue to use well known 

 generic names until the necessary changes can be placed upon a 

 sound basis. At present, the dentition of Tornatina is absolutely 

 unknown ; and as that name has become well established in conch- 

 ological nomenclature, I consider that no good end would be reached 

 by reducing it to a subgenus of Retusa a course inevitable if 

 Fischer's ideas are followed to their logical conclusions. 



This genus consists of small and minute shells, white or light 

 brown in color, with peculiarly projecting, teat-like, uptilted, nuclear 

 shell and one small columellar fold. The distribution of the group 

 is practically world wide. They live at moderate or considerable 

 depths, and probably subsist mainly upon Foraminifera. The 

 species are numerous, but not especially difficult to distinguish if 

 properly described and figured ; but, unfortunately, a considerable 

 number of A. Adams' forms are known by poor, small figures only, 

 with insufficient descriptions ; so that until these are refigured from 

 the types, their identification will not be easy. 



Species of the Azores and West Africa. 



T. PROTRACTA Dautzenberg. PI. 25, figs. 39, 40, 41. 



Shell 1*5 mill, high, '75 mill, wide, ovate-cylindrical, convoluted, 

 very shining ; first whorl intorted, very much projecting ; last whorl 

 rather flattened below the suture, then becoming rather convex. 

 Surface smooth, with very fine growth-lines only. Aperture elon- 

 gated, contracted above, dilated toward the base ; columella simple, 

 arcuate ; lip sharp, subarcuate ; color white, throughout (Dautz). 



Pico, Azores, in 1287 meters. 



Tornatina protracta DAUTZ., Res. Campagnes Sci. Prince Albert 

 I, p. 22, pi. 1, f. 4, 1889. 



In its general form, as well as the conformation of the apex, this 

 species approaches T. lepteJces Wats., but it is smaller, less elongated, 

 with fewer whorls. 



