1917. 



NATURAL SCIENCES OF PHILADELPHIA. 



315 



The initial whorl is low, with iiiturned tip, following whorls are 

 convex, regularly increasing, very densely microscopically striate 

 spirally. The suture is narrowly channelled. The slopes of the 

 spire are nearly straight. The aperture is ovate, oblique. The 

 columella bears a small fold, visible in oblique view in the mouth, 

 but so far immersed that it is not seen in direct front view. 



Length 6.7, diam 1.65, length of aperture 1.65 mm.; 10 whorls 

 (type). 



Length 7.6, diam. 2, length of aperture 1.7 mm. (largest specimen 

 seen) . 



Fig. 9. — Turbonilla dizabelhcE. 9a. — A young speci- 

 men from Honolulu, length 2.8 mm. 



Fig. 10. — Turbonilla laij- 

 sanensis. 



This pretty, delicately colored shell is named for Mrs. W. A. Bryan. 

 The nuclear whorl is so far immersed that it resembles that of Odos- 

 tomia. By Dr. Bartsch's kej^, it runs nearest to the subgenus Care- 

 Jiopsis MOrch; but that differs by the characters of the nuclear shell. 

 T. eUzabethce is here made the type of a new subgenus to be called 

 Evaletta, characterized by the low, inturned nuclear whorl and the 

 evenly convex whorls, microscopically striate spirally. The length- 

 ened form and numerous whorls separate it from Odostomia, wherein 

 it approaches the subgenus Evalina somewhat. 



Turbonilla (Evaletta) laysanensis n. sp. Fig. 10. 



Laysan Island. Type No. 117627, A. N. S. P., collected by W. 

 A. Bryan. 



Shell similar in color and shape of the whorls to T. elizahethce, but 

 of decidedly broader form, and of fewer whorls in a shell of greater 

 length. The type has lost the nuclear whorl. 



Length 8.7, diam. 2.2 mm.; 8 post-nuclear whorls. 



