1906. 



NATURAL SCIENCES OF PHILADELPHIA. 



215 



ON HAWAIIAN SPECIES OF SPHYRADITIM. 



BY HENRY A. PILSBRY AND C. M. COOKE, JR. 



The genus Sphyradium occurs over practically the whole Palsearctic 

 and Nearctic realms, with one species in the Neotropical, but it has not 

 hitherto been reported from Polynesia. The two Hawaiian species to 

 be described below have all the shell characters of the genus, but since 

 the jaw and teeth of neither is known, their reference to Sphyradium 

 is provisional. 



Sphyradium sharpi P. and C, n. sp. Figs. 1, 2. 



The shell is narrowly umbilicate, tapering-cylindric, the summit 

 obtusely conic; thin; chestnut brown, paler near the apex, the surface 

 somewhat shining and distinctly but not closely striate. Whorls 

 slightly over 5, quite convex, the suture deeply impressed. The aper- 

 ture is strongly oblique, rounded lunate. Peristome thin and simple, 

 the basal and outer margins well arched ; columella vertical with broadly 

 dilated edge. The insertions of the lips are remote. The umbilicus 

 is circular and deep. Length 1.8, diam. 1.36 mm. 



Hawaii : Crest of the Kilauea crater, about a half mile south of the 

 hotel. Types No. 91,699, A. N. S. Phila., collected by Dr. Benjamin 

 Sharp. Cotype in the Bernice Pauahi Bishop Museum at Honolulu. 



This species is closely related to the following, from which it differs 

 in being somewhat larger but with a smaller number of whorls. The 



Fig. 1. 







Fig. 2. 



Fig. 3. 



shape also differs perceptibly, S. alexanderi being noticeably more egg- 

 shaped, with a rounded summit. It is also less strongly striate and 



