BY THE REV. J. E. TENISON-WOODS. 
1073 
p. 377, pi. 47, figs, 11-12 ; Gray, Cat. Phan. p. 93 = M anosfoma, 
Pfv. Mon. Pneumon. Suppl. I. p. 85. 
Labuan, Borneo. 
M. LEFERi, Morelet = Cyclostoma leferi, Morelet, Jour. Conch. 
IX. 1861, p. =2Legalomastoma leferi, von Mart. Ostas. Zool. 
II. p. 154 3 Pfr. Mon. Pneumon. Suppl. III. p, 138. 
Borneo. 
M. DORiAE, Issel, Moll. Born. 1874, pi. 67, pi. 6, figs. 18-19 • 
Pfr. Mon. Pneumon. Suppl. III. p. 138. 
Sarawak, Boxmeo. 
M. (CoPTOCHiLUs) SECTiLABRUjr, Goulcl ; von Moll. Jour. As. 
Soc. Beng. LV. 1886, p. 314. 
Perak ; Larut ; Penang. 
32. Hybocystis, Benson, 1859, Annals and Mag. Nat. Hist. 
3rd ser. IV. p. 90. 
This remarkable and exceedingly interesting genus, which forms 
one of the peculiar features of the terrestrial molluscan fauna of 
the Malay Peninsula, deserves the fullest details in this list. 
Fortunately its history as a species has been well marked out by 
M. P. Fischer in the “ Jouimal de Conchyliologie”(XXY. 3rd series, 
1885, p. 180), an epitome of whose researches will now be given. 
The genus was proposed by Benson in 1859 for a Burmese 
shell which had been hitherto described as a species of Megaloma- 
stoma, and in its young stages as a species of Otopoma. Some 
years before Dr. Gould, the American naturalist, had described 
the same shell, for which he had proposed the generic name of 
Pollicaria ; but as the genus was insufficiently defined, and 
inclucled species of different genera, Benson’s genus has been 
preferred as complying with every condition of necessary exact- 
ness. 
The shell is ovoid and im|)iforin, but deviating from its axis 
in the last whorls in the manner of certain species of Streptaxis. 
The ante-penultiniate whorl is much developed and flattened in 
