264 EMARGINULA. 



E. JAPONICA Sowerby. PL 28, fig. 18. 



Sub-purple, subelliptical, conical, narrower behind, sides com- 

 pressed, apex obtuse ; fissure small ; ribs unequal, rugose ; posterior 

 margin thickened within. Distinguished by a compression of the 

 sides, the narrowness of the posterior end, and the thickening of the 

 inner posterior edge. (Sowb.) 



Japan. 



Kjaponica SOWB. Thes., p. 216, f. 43, 44. 



E. FISSURATA Chemnitz. PL 29, figs. 28, 29. 



Depressed-conical, wide, red, solid ; apex obtuse, median ; radiat- 

 ing ribs numerous, minutely nodulous, interstices smooth ; fissure 

 small, a callus extending upward from it inside. (JSowb.") 



Philippines. 



Patella fissurata CHEMNITZ, Syst. Conchyl. Cab. xi, p. 188, 1. 197, 

 f. 1929, 1930. Emarginula fissurata AD. P. Z. S. 1851, p. 82. 

 SOWB. Thes., p. 216, f. 104. j. rubra LAMARCK. 



Group of E. incisura. 



Shell depressed ; apex nearer to the center than to the posterior 

 end ; basal side-margins arched, so that the ends alone support it. 



Besides the following species, E. huzardi of the Mediterranean 

 belongs here. 



E. THOMASI Crosse. PL 21, fig. 26. 



Shell ovate, slightly convex, compressed, narrower in front, 

 rounded behind, very elegantly decussated with numerous longitu- 

 dinal stibequal riblets and subflexuous concentric lines ; pale green ; 

 apex central, obtuse ; fissure very broad ; slit-fasciole having the 

 edges elevated, crossed by transverse lamellae ; interior green, pale 

 brown in the middle; margin crenulated. Length 22 i, breadth 

 16, alt. 6 mill. ; Length of fissure 5, width 2 mill. (Crosse.) 



A den, entrance to the Red Sea. 



E. thomasi CROSSE, Journ. de Conchyl. 1864, p. 43, 152, t. 7, f. 1. 



A remarkably large and depressed species, unlike any other. 



E. PLANULATA A. Adams. PL 28, fig. 15. 



Elongate-oval, complanate, summit subcentral, inclining back- 

 ward ; whitish ; decussated with equal imbricately-roughened radiat- 

 ing riblets and concentric lines of increment ; base arcuate ; margin 

 of the aperture deeply incised in front, the slit broad and deep. 



