OPISTHOP0lt¥S. 
27 
4. O. tisbuliferus Pfp. 
T. late umbilicata, clepressa, striatula, opaca, albida, flam- 
mis angulosis fuscis pi eta ; spira vix elevata, fusco-violacea, 
vertice subacute prominente; sutura subprofimda; anfr. 4^ 
convexiusculi , ultimus teres, antice breviter solutus, vix de- 
scenders, 2 mill, pone aperturam tubulo brevi a sutura antror- 
sum subascendente munitus; apertura diagonalis, circularis; 
perist. duplicatum : internum continuum , porrectum, externum 
marginibus supero et dextro breviter patens, sinistro obsole- 
tum. — Operc. ? — Diam. maj. min. 13, alt. 6 2 / 3 mill. 
Ap. diam. 6 mill. (Mus. Cuming.) 
Cyclostoma tubuliferum (Cyclotus) Pfr. in Proc. Zool. Soc. 1853. p. 51. 
Cy dolus tubuliferus Pfr . in Malak. Bl. 1854. p. 81. 
Opisthoporas tubuliferus Berts, in Ann. and Mag. 2d. ser. XV. p. 14. 
— — H. et A. Adams Gen. rec. Moll. II. p. 277. 
Habitat . . .? 
5. O. birogtris Pfr* 
T. umbilicata, depressa, subdiscoidea , solidula, irregula- 
riter striata, fulvo-lutea, fascia peripherica castanea et superne 
strigis latis angulatis ornata; spira plana, vertice subtili, vix 
prominulo; anfr. fere 5 convexiusculi, rapide accrescentes, 
ultimus teres, subtus obsolete maculatus, antice solutus et 
tubulo antrorsum curvato munitus; umbilicus latus , anfractus 
omnes latiores et convexiores monstrans quam superne; aper- 
tura diagonalis , circularis ; perist. duplex : internum breve, 
rectum , externum expansum et inflexum , superne in rostrum 
apertum , anfractum ultimum tangens , productum. — Operc. 
album, arctispirum, extus concavum. — Diam. maj. 26, min. 
19, alt. 7 mill. Ap. intus 7 mill. diam. (Coll. Nr. 35.) 
Cyclostoma biroslre (Cyclotus) Pfr. in Proc. Zool. Soc. 1854. p. 300. 
Habitat Sarawak, Borneo. 
6. €1. pi ero cycloid es Pfp- 
T. umbilicata, depressa, subdiscoidea, solidula, striatula 
et striis spiralibus sub lente decussata, lutea, strigis angulatis 
castaneis picta; spira plana, vertice mucronatim prominulo; 
anfr. 5 rapide accrescentes, parum convexi, ultimus depresso- 
rotundatus, antice solutus et spiraculo antrorsum vix ascen- 
dente munitus; umbilicus profundus, 4 / 3 diametri superans; 
apertura diagonalis, circularis; perist. duplex: internum vix 
porrectum, superne leviter emarginatum, externum dilatatum, 
rectangule patens, limbo subinflexo, superne subangulatim pro- 
