PRONESOPUPA. 6 



HAWAIIAN SPECIES OF PRONESOPUPA. 



BY C. MONTAGUE COOKE AND H. A. PILSBRY. 



The shells are minute (1.4 to 2.7 mm. in length), fragile, 

 dextral, perforate, ovately conic to conic-helicoid, costate, 

 with 4 to 51/2 whorls. The embryonic whorls are minutely 

 granulose. Aperture without palatal plica; in one species 

 (P. boettgeri) there are one or two minute lamellae on the 

 parietal wall and occasionally there is a swelling or a minute, 

 deeply-seated fold on the columella. Lip insertions remote. 



The animal is like Lyropupa, Nesopupa and Vertigo in 

 lacking inferior tentacles. No muscular waves of the sole 

 were noticed in crawling. 



Nearly all the species are arboreal in habit, being found 

 either on the trunks of trees, the branches of bushes or on the 

 leaves of low-growing plants. A very few specimens have 

 been taken on the ground, on mossy stones or dead leaves, 

 probably fallen from plants. 



Key to Subgenera and Species of Hawaiian Pronesopupa. 



a 1 . Adult shells with 4-4^4 whorls; costee with membranous 

 margins, often forming spine-like processes at the shoul- 

 der. 



6 1 . Surface of embryonic whorls minutely granulose, 

 and in addition, furnished with very minute raised 

 spiral lines; 35-40 costee on the last whorl (Section 

 Edentulopupa). P. admodesta, no. 7. 



Zr. Surface of embryonic whorls minutely granulose, 

 the granules arranged in transverse rows, and with- 

 out spiral lines; 20-30 costae on the last whorl (Sec- 

 tion Pronesopupa proper) . 



c 1 . Costes uniform in height, not armed with 

 spines. P. acanthinula, no. 3. 



c 2 . Costae armed with spines. 



d 1 . Aperture without teeth. 



e 1 . Diameter 80-85% of the length. 



P. T). spinigera, no. 6. 

 e 2 . Diameter 95-100% of the length. 

 P. hystricella, no. 4. 



