154 F. Stoliczka — Notes on terrestrial Mollusca. [No. 2, 



Asiat. Soc. Bengal, vol. XXXIX, pt. II, pi. ii, fig. 3-5), in the 

 short internal parietal rib just at the beginning of the last whorl, 

 and in the twisted columella which terminates in the aperture with a 

 tooth, sometimes placed so far internally as to be hardly visible, 

 but very rarely becoming nearly obsolete. In addition to these 

 characters the typical species have the whorls either partially or 

 wholly transversally costulate or striated, and the shell itself is of a 

 moderately solid structure. 



Semper instituted the genus Palaina for a number of Philippine 

 species, some of which, like P. polymorplia, P. strigata, and others 

 (see J. cle Conch. 1866, pi. ii and x,) do not in any way differ from 

 typical Indian Diplommatince . In other species, noted by Semper, as 

 for instance in P. pitfa^patula, Wilsoni, &c, the general character of 

 the shell is the same, the constriction more or less distinctly marked, 

 but the columellar tooth is not visible. The same can be observed 

 in some allied Himalayan forms, as D. Huttoni or costulata, though 

 looking into the aperture obliquely, the abrupt termination of the 

 columella may, for instance in the last-named species, be readily 

 seen. I do not think it, therefore, improbable that the terminal twist 

 and truncature of the columella also exists in these Pelew, or Philip- 

 pine, Palaince, in which case there would be no reason whatever to 

 separate them generically, or subgenerically, from Diplommatina. 



Other species, again, like Pal. pyramis, alata and lamellata of 

 Semper (1. cit.) are distinguished by a round, almost tubular aper- 

 ture, with a free sharp continuous margin, being internally con- 

 spicuously thickened and obliquely placed towards the axis of the 

 shell ; the whorls are ornamented with transverse lamellar ribs, 

 mostly projecting at the middle, the penultimate whorl is not dis- 

 tinctly constricted, and the columellar tooth is in some visible, in 

 others not, though I have little doubt but that in all the columella is 

 twisted and in the interior of the aperture truncated. For this group 

 the name Palaina may be retained, but only as a subgenus of Diplom- 

 matina ; for on comparing species like Blanford's I). exilis from Ava, 

 it will be readily seen how closely connected all these forms are. 



For Mousson's Pupa problematica, from the island Upolu, Semper 

 proposed the subgeneric name Moussonia, changing (why ?) the 

 specific into typica (comp. J. de Conch., 1865, p. 296, and 1866, pi. 



