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



Luzon, (vide Journ. de Conch, for 1866, p. 852). Armies are small 

 shells, allied to Diplommatincd, but of a thin structure, with smooth, 

 or nearly smooth, surface, without a distinct constriction on the 

 penultimate whorl, and without a fold on the columella. 



Mr. W. T. Blanford (Journ. Asiat. Soc. xxxvii, 1868, p. 82, and 

 also Journ. de Conch, for 1868) proposed the name Nicida for 

 six species from South India. Three of these N. Pulneyana, liri- 

 cincta, and Kingiana, do not externally appear to offer any generic, 

 or sub-generic, distinction from Arinia. In all these the position of 

 the small operculum when retracted is exactly the same as in 

 Diplommatina, and the same internal parietal plait exists at the be- 

 ginning of the penultimate whorl ; the collumella is twisted, with a 

 fold, but the latter becomes obsolete at the aperture, not terminating 

 in a tooth. Mr. Blanford, therefore, very properly stated that Nicida 

 must only be considered as a subdivision of Diplommatina, on 

 which point there can be no doubt. I have seen the animal of 

 Nic. liricincta, and it is exactly like that of Diplommatina. It 

 does not appear to me at all improbable that Arinia and Nicida 

 will have to be united into a single subgenus ; Sowerby's figure 

 of minus is rather in favour of this view, but I have not that 

 species for comparison and in order to settle the relation which 

 is supposed to exist between Arinia and Nicida, it is absolutely 

 necessary that the internal structure of the ultimate and penultimate 

 whorls of the two species of Arinia be compared with these same 

 parts of the shell of Nicida. If a twisted columella and a parietal 

 rib do not exist in Arinia, the genus will have probably to be 

 placed near Callia and Streptaulus in the PupiNEDiE. 



"With regard to Mr. Blanford' s three other species of Nicida : 

 N. nitidula shews a very slight constriction of the penulti- 

 mate whorl, and Nilgirica (the type) and Fairlcanlci have it very 

 distinctly developed externally. They, therefore, only differ from 

 Diplommatina by the thin structure of their shells, and by the 

 want of transverse costulation on the whorls. 



To sum up — we have in the Diplommatina group of Pneumo- 

 nopoma, 1st, the genus Diplommatina, with the subgenera (a) Palaina 

 (of the type of P. pyramis, Semp.), (b), Moussonia, (with the type 

 Mouss. problematica (alias typica), the subgenus being only admissible, 



