1920.] NATURAL SCIENCES OF PHILADELPHIA. 361 



6. Summit narrowly, deeply umbilicate 7 



Summit imperforate or barely perforate 8 



7. Shell larger, in large part smooth, marbled with brown. 



Bulla7ia Raf. 

 Shell small, spirally sculptured throughout, often banded. 



Mnestia Ads. 



8. Axial margin above the summit folded Atys Helbl. 



Axial margin not folded above 9 



9. Columella abruptly truncate anteriorly Dinia Ads. 



Columella slightly concave, indistinctly truncate anteriorly; 



shell having incised spiral lines throughout. 



Haminoea, subg. Liloa. 

 Columella broadly, strongly concave, not truncate 10 



10. A thm, broad, spiral plate posteriorly on columella; shell green, 



shaped like a split bean Smaragdinella Ad. 



No such columellar plate; light colored 11 



11. Summit produced in a narrow spout; shell very fragile, showing 



the interior in a basal view Volvatella Pse. 



Summit not produced 12 



12. ■ Summit rather narrow, not impressed over the axis ; aperture 



very ample below Scaphander Montf. 



Summit rounded, impressed in the center . . Haminoea T. & K. 



ACTEONIDiE. 



Three species of the genus Pupa Bolt. (SoUdula F. deW.) have been 

 found. P. nitidula (Lam.), a widely dispersed species, is known 

 from the Islands by specimens in the collection of the Academy from 

 Dr. Newcomb. It has not been found by any recent collector, so 

 far as I know. It seems possible that Newcomb's shells were from 

 Polynesia. In his time many shells from the southern islands were 

 coming into Honolulu in the missionary schooner Morning Star, 

 and sold there for the benefit of missions. 



1. Nearly white; smooth save for a group of spiral grooves at the 



base; spire very short, apex mamillar; columellar fold very 

 heavy and prominent. Length 17, diameter 9 to 10 mm. 



P. nitidula (Lam.) 



Spirally grooved at summit and below middle of last whorl, or 



throughout; spire conic 2 



2. Deeply grooved spirally throughout; 9 x 4 to 11.5 x 5.1 mm. 



P. thaanumi Pils. 



