BY THE REV. J, E. TENISON-WOODS. 1061 



22. Opisthoporus, Benson. 



Zeitschr. f. Malak. 1851, p. 8 ; Pfr. Mou. Pneumon. Viv. 

 Suppl. 111. p. 41 ; Zeitschr. f. Malak. 1851, p. 8 ; Pfr. Mon. 

 Pneumon. Viv. Suppl. I. p. 25, TI. p. 36. 



Shell depressed, orbicular, largely uuibilicate ; aperture double, 

 with the external parts spi'ead out ; suture behind the opening 

 and furnished with a little open tube ; operculum calcareous, 

 circular, rather thick, concave at both sides, multispiral, double ; 

 the internal side covered with a horny periostraca, the external 

 calcareous and rough ; columella margin concave. 



Opisthoporus solutus, Stol. Jour. As. Soc. Beng. XLT. 

 1872, p. 266, pi. 10, figs. 8-10 ; Pfr. Mon. Pneumon. Suppl. III. 

 1876, p. 44 ; G. Nevill, Handl. Moll. Ind. Mus. 1878, p. 263 ; 

 H. Crosse, Jour. Conch. XXVII. 1879, p. 337. 



Bukit Pondok ; Penaug. 



O. PENANGENSis, Stol. l.c. 1872, p. 265, pi. 10, fig. 7 ; Pfr. 

 Mon. Pneumon. Suppl. III. 1876, p. 43 ; G. Nevill, Handl. 

 1878, p. 263; H. Crosse, Jour. Conch. XXVII. 1879, p. 338. 



Bukit Pondok ; Penang. 



O. JAVANUS, Pfr. Malak. Bl. VII. 1860, p. 215, pi. 3, 

 figs. 8-10; Mon. Pneumon. Suppl. II. 1865, p. 37. 



Nungnang, Java. 



O. SUMATRANUS, von Mart. Monatsber. Bei-1. Ak. 25 Feb. 

 1864; Pfr. Mon. Pneumon. Suppl. II. 1865, p. 37. 



Sumatra. 



C?) O. SPINIFERUS (Cyclostoma), Morelet, = Cyclosfoma spini- 

 ferum, Morelet, Jour. Conch. IX. 1861, p. \7 7 = Opisthoporus 

 spiniferus, von Mart. Ostas. Zool. II. p. 113 ; Pfr. Mon. Pneu- 

 mon. Suppl. III. p. 41. 



Borneo. 



O. PERTUSUS (Cyclostoma), Morelet ; Issel, Moll. Born. p. 75 ; 

 Pfr. Mon. Pneumon. Suppl. III. p. 43 = Cyclostoma perttcsum^ 

 Morelet, Jour. Conch. IX. 1861, p. 177. 



Borneo. 



