640 PROCEEDINGS OF THE ACADEMY OF [Dec. , 



developed lowei' palatal plica, as it is no doubt iu part homologous 

 Avith that. 



The shell is excessively solid aud thick, sti'onger in fact than any 

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

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

 Yaku-shima, common to the StereopJuedusa', Hemiplwdusa' and 

 TyramioplueduHa' alike, aud clearly to be correllated with some 

 factor in the environment acting upon the entire series. 



EXPLANATION OF PLATES XXXV-XXXIX. 



Plate XXXV (Hemiph^edusa). Figs. 1-6. — ClausiUd Mgoensis. Types. 



Figs. 7-10. — Ctausilid ptychocyma. Type. 



Fig. 11. — Clausilia ptychocyma vav. YakusMince. Type. 



Figs. 12-14. — Olaiisilia Pinto. Type. 



Fig8. 15, 16. — Clausilia ischna. Type. 



Plate XXXVI (Tyraxnoph^edusa). Figs. 17-21. — ChtusiUa hilabrata. 

 Specimen-^ Irom Kobe, the type locality. 



Fig. 22. — Clausilia. hilabrata. Specimen retaining the apical whorls, 

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



Figs. 23, 24. — Clausilia hilabrata . Specimens from Takaya, in which 

 the snrlace is corroded, covered with algse dorsallv. No. 79,719 Coll. 

 A. N. S. P. 



Fig>. 25-29. — Clausilia surugensis. Types. 



Figs. SO-31. — Clausilia Oscariana. Types. 



Plate XXXVII (Tykaxxoph.edusa). Figs. 32-34.— Claasilia tanega- 

 sMmce. Type. 

 Figs. 35-38. — Clausilia oxycyma. Types. 

 Figs. 39, 40. — Clausilia tanegashitna. 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 brevier. 

 Specimen from Coll. E. R. Sykes 



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

 Coll. A. N. S. P. 



Figs. 54-57. — Clausilia Addisoni. Types. 



Figs. 53-62. — Clausilia Jacobiana. Tancgashima, Osumi. 



Plate XXXIX (STEREOPHYf:r)USA). Figs. 03-65. — Clausilia stereoma. 

 Clausilium, Fig. 64, from the coiumellar edge. 



Fig.i. 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. 71-77. — Clausilia entospira. Type. Figs. 76, 77 reconstructed 

 from a broken clausilium. 



Figs. 7S, 79. — Clausilia stereoma var. nugax. Type. 



