280 SUBP:MARGINULA. 



S. ASPERA Gould. PL 41, figs. 40, 41, 42, 43. 



Four principal posterior ribs double ; about 10 primary ribs. 



Shell oval, elevated or depressed, apex subcentral ; sculptured 

 \vith about 10 principal ribs, four of the posterior ones double or 

 divided by a median groove ; interstitial riblets irregular, variable 

 in number. Concentric strise nearly obsolete in adults, fine and 

 obsoletely prickle-scaly in the young. Color grayish-white or 

 chocolate-brown between the larger ribs. Inside white, with or 

 without dark radiating stripes ; no distinct mushroom-shaped pat- 

 tern inside the muscle-scar ; anterior groove very short, but the 

 notch rather deep ; margin thick, obsoletely, irregularly crenulated, 

 the marginal denticles about 50 in number. 



Length 20, width 14, alt. 8 mill. 



Length 18, width 13, alt. 13 mill, (most elevated seen). 



Fiji, Viti and Philippine Is. ; S. Australia f 



E. aspera GOULD, Proc. Bost. Soc. K H. ii, p. 154, 1846 ; U. S. 

 Exped. Sh. p. 372, atlas, f. 4Q3.E. cinerea GLD., I. c. p. 155 : atlas 

 to Exped., f. 494. Subemarginula crassilabrum A. AD., P. Z. S. 

 1851, p. 91. SOWB., Thes. p. 217, f. 79. f S. sculptilis AD., P. Z. 

 S. 1851, p. 92. 



I have considered the double posterior ribs, short sulcus, etc. to 

 be diagnostic points of a species ; and have united certain described 

 forms which agree in these characters. The type of aspera (pi. 41, 

 figs. 40-43) is a young shell. E. cinerea Gld. (pi. 41, figs. 28-31) 

 from Fiji Is. may be distinct. It is thinner, and has a mushroom - 

 shaped pattern inside, but the posterior ribs are double. E. crassi- 

 labrum Ad. (pi. 29, fig. 16), and E. ossea Gld. (pi. 41, figs. 22-25) 

 from the Fiji Is. do not seem to differ. 



S. SCULPTILIS A. Adams. PI. 29, fig. 19. 



Oval, obliquely conical, whitish, radiately maculated with green ; 

 summit subcentral, deeply declining backward ; corrugated by 

 radiating ribs, the interstices beautifully punctate-clathrate ; prom- 

 inent anterior rib crenulated ; margin of aperture undulated and 

 crenulated, rounded behind, truncated and sinuous in front, the 

 sinus produced into a channel inside. Clath rated as in E. Panhiensis, 

 but not so elevated and more compreesed at the sides, with a brown 

 marginal spot between each of the larger ribs. (Ad.) 



Calapan, Island of Mindoro, Philippines. 



Subemarginula sculptilis AD. P. Z. S. 1851, p. 92. E. sculptilis 

 SOWB. Thes. p. 218, f. 89. E. sculptilis SOWB. in Conch. Icon. f. 53. 



