LYROPUPA. 233 



Species from Kauai and Oahu have the surface of the em- 

 bryonic whorls wrinkled-granulose (except L. microthauma.). 

 Those from Molokai, Lanai. Maui and Hawaii have the em- 

 bryonic whorls minutely, closely, spirally striate. 



The two Oahuan species are quite distinct, but L. lyrata 

 has numerous local races or forms not yet fully worked out. 

 L. truncata of HaAvaii is one of the most characteristic of the 

 genus, but. the other known species of Molokai, Lanai, Maui 

 and Hawaii are closely related and by no means conspicuously 

 differentiated. The following key is given as an alternative to 

 that on p. 229 ; it is based upon more natural characters, but 

 partly not to be observed in worn or fossil specimens. 



a 1 . Embryonic whorls minutely granulose-wrinkled ; Calm. 



L. lijrata, no. 1. 

 a 2 . Embryonic whorls minutely striate spirally. 



6 1 . Later whorls very closely striate spirally. 

 c 1 . Summit bluntly rounded. 



c? 1 . Ribs numerous; Maui. 



L. tJuiaiiumi, no. 4. 

 d~. Ribs rather widely spaced ; Molokai. 



L. rhabdota -plur-is, no. 3. 

 c 2 . Summit subconic. 



d 1 . Length 1.8 to 2.1 mm.; Oahu. 



L, microthauma, no. 2. 



d 2 . Length 2.5 to 2.7 mm. ; Molokai, Lanai 

 and Maui. L. rhabdota, no. 3. 



d ''. Length 2.7 to 3.1 mm. ; Hawaii. 



L, prisca, no. 5. 

 b 2 . Later whorls distantly striate spirally ; Hawaii. 



c 1 . Summit subconic. L. clathrotula, no. 6. 



c 2 . Summit abruptly truncate. L. trinicata, no. 7. 



1. LYROPUPA LYRATA (Old.). PL 19, figs. 1 to 6. 



"The shell is small, most generally siuistral, chestnut 

 colored, widely umbilicate; 5 convex whorls, with about 20 

 neatly clathrate flexuous riblets ; aperture somewhat orbicular, 

 bell-shaped, posteriorly armed with two lamella-like teeth and 



