646 PROCEEDINGS OF THE ACADEMY OF [Dec., 



developed lower palatal plica, as it is no doubt in part homologous 

 with that. 



The shell is excessively solid and thick, stronger in fact than any 

 other species of such diminutive stature known to me; but unusual 

 solidity is a characteristic of the Clausilise of Tane-ga-shima and 

 Yaku-shima, common to the Stereophcedusce, Hemiphcedusce and 

 Tyrannophcedusce alike, and clearly to be correllated with some 

 factor in the environment acting upon the entire series. 



EXPLANATION OF PLATES XXXV-XXXIX. 



PLATE XXXV (HEMIPH^DTJSA). Figs. 1-6. Clausilia Jiigoensis. Types. 



Figs. 7-10. Clausilia ptychocyma. Type. 



Fig. 11. Clausilia ptychocyma var. Takushimce. Type. 



Figs. 12-14. Clausilia Pinto. Type. 



Figs. 15, 16. Clausilia ischna. Type. 



PLATE XXXVI (TYRANNOPH^DUSA). Figs. 17-21. Clausilia bilabrata. 

 Specimens from Kobe, the type locality. 



Fig. 22. Clausilia bilabrata. Specimen retaining the apical whorls, 

 from Ushirosawa, Tosa, No. 81,926 Coll. A. N. S. P. 



Figs. 23, 24. Clausilia bilabrata. Specimens from Takaya, in which 

 the surface is corroded, covered with algse dorsally. No. 79,719 Coll. 

 A. N. S. P. 



Figs. 25-29. Clausilia surugensis. Types. 



Figs. 80-31. Clausilia Oscariana. Types. 



PLATE XXXVII (TYRANNOPH^DUSA). Figs. 32-34. Clausilia tanega- 

 shimcB. Type. 



Figs. 3o-38. Clausilia oxycyma. Types. 

 Figs. 39, 40. Clausilia tanegashima. Clausilium. 

 Figs. 41, 42. Clausilia oxycyma. Clausilium. 

 Fig. 43. Clausilia orthatracta. Clausilium. 

 Figs. 44-46. Clausilia orthatracta. Type. 



PLATE XXXVIII (STEREOPH^EDUSA). Figs. 47, 48. Clausilia brevior. 

 Specimen from Coll. E. R. Svkes 



Figs. 49-53. Clausilia bremor. Specimens from Tokyo. No. 18,801 

 Coll. A. N. S. P. 



Figs. 54-57. Clausilia Addisoni. Types. 



Figs. 53-t>2. Clausilia Jacobiana . Tanegashima, Osumi. 



PLATE XXXIX (STEREOPH^DUSA). Figs. 63-65. Clausilia stereoma. 

 Clausilium, Fig. 64, from the columellar edge. 



Figs. 66-69. Clausilia jacobiana. Fig. 68 represents the palatal arma- 

 ture of an immature shell. 



Figs. 70, 71. Clausilia stereoma. Type. 



Figs. 72, 73. Clausilia entospira. Fig. 72 is an oblique view in the 

 aperture, from below and the left side. 



Figs. 74-77. Clausilia entospira. Type. Figs. 76, 77 reconstructed 

 from a broken clausiliutn. 



Figs. 78, 79. Clausilia stereoma var. nugax. Type. 



