64 JAPANESE MOLLU8K8, FOSSARID^E. 



Lacuna stenotomorpha Pilsbry. PI. VIII, fig. 3. 



Shell small, smooth, yellow, with a white band at periphery and 

 another below the suture ; depressed, oblique, with large, open, ex- 

 cavated white umbilicus. Spire low, last whorl very rapidly enlarg- 

 ing, descending in front, rounded at periphery. Aperture ovate, 

 oblique, small ; outer lip well curved, inner lip nearly straight. 

 Umbilicus deep, encircled by an acute keel, excavated on its inner 

 surface. Alt. 4, diam. 4 mm. ; aperture, oblique alt. 3, width 2 mm. 



Tokyo Harbor (Stearns). 



In this species the form approaches Stenotis laxata. The last 

 whorl is marked off from those preceding by a dark line, probably 

 indicating the end of the larval stage. This is visible in the two- 

 other species herein described, but I do not notice it in the North 

 Atlantic or Californian Lacunas. This feature may indicate a sect- 

 ion or subgenus, which may be called Sublacuna. 

 Lacuna (Stenotis) laxata A. Ad. Journ. de Conchy]., 1868, p. 54, pi. 4, f. 7. 



Idzuma-Nada, Inland Sea, 17 fms. ; Yobuko, W. coast of Kiushiu,. 

 14 fms. (Ad.). 



F088ARIDJE. 



Fossarus costatus Brocchi. Conch. Foss.Subap., p. 300, pi. 11, f. 11 ; Fossar japon- 

 icwA. Ad., Ann. Mag., 1861, p. 139. 



Kuro-Shima, Tsu-Shima (Ad.). 

 Fossarus trochlearis A. Ad. P. Z. S., 1853, p. 187. 

 O-Shima (Ad.). 



Fossarus fenestratus A. Ad. O-Shima (Ad.). 

 Couthouya deoussata A. Ad. Ann. Mag., 1860, p. 410. 



Mino-Shima (Ad.). 

 Couthouya reticulate A. Ad. P. Z. S., 1853, p. 186 (Fossar). 



Seto-Uchi, Uraga (Ad.). 



Couthouya striatula and C. plicifera A. Ad. Yobuko (Ad., I c.) 

 Isapis lirate A. Ad. Ann. Mag., 1860, p. 120. 



Mino-Shima, Uraga (A. Ad.). 

 Isapis conoidea A. Ad. Takano-Shima (Ad.). 

 Conradia cingulifera A. Ad. Ann. Mag., 1860, p. 410. 



Mino-Shima, Uraga (Ad.). 



Conradia carinifera A. Ad. Mino-Shima, Goto (Ad., I. c.). 

 Conradia clathrata A. Ad. Tsu-Shima, Goto (Ad.). 



