Hawaiian Species of Helicina. 



Rv Henry a. I'ii.sbry and C. Montague Cooke, Jr. 



Helicina, in company with other genera of the smaller 

 Hawaiian land shells, has so far received very little attention from 

 the local collectors. The present paper is based mainly on a 

 series collected for the Bishop Museum by the junior author. 



The Hawaiian species are very seldom found alive in open 

 or partly open country. They are usually collected in rather damp 

 and heavily wooded sections of the islands. The only exception 

 is H. baldwini, which occurs in a rather open belt of hala (Pan- 

 danus odoratissimus) , on the fallen leaves. 



The representatives of this genus, from the Hawaiian Islands, 

 seem to belong to three groups. The characters upon which these 

 groups are based, at present, are only those of the shell. 



I. Group of H. laciniosa. In this group the spire is conic or 

 depressed-conic, the periphery is more or less angular and the last 

 whorl is flat or nearly flat above the periphery. This group con- 

 tains : laciniosa and its numerous varieties, oahuensis, sukulosa, 

 nuuanuensis and baldwini. 



II. Group of H. rotelloidea. This group is characterized by 

 the shells having a somewhat rounded periphery, the whorls are 

 distinctly convex. The species belonging to this group are as 

 follows: rotelloidea, hawaiiensis , k?itidse?ii and kauaie?isis. 



III. Group of H. ubcrta. In this group the periphery is 

 rounded, the whorls are nearly flat, the spire rather high with 

 distinctly convex outlines and the aperture is sometimes slightly 

 contracted. The species belonging to this group are: tiberta and 

 its var. magdalencz, berniceia, lymaniana and juddii. 



Helicina oahuensis, n. sp. 



Fig. i. 



The shell is lenticular, with the periphery acutely carinate, 

 slightly sinuous and minutely crenulated by the growth -striae, 

 thin, slightly diaphanous, striate with lines of growth, with two or 

 three faint impressed spiral lines on the upper portion of the whorls 



[i99] (3) 



