ABIDA. 



smaller dimensions, more subcylindric shell which is not fusi- 

 form above, by the deeper suture, and the less rapid increase 

 of the whorls. The disposition and number of the teeth and 

 lamellae is quite similar in the two forms, but the palatals and 

 columellars are less robust in limonensig, and the parietals are 

 stronger. Moreover, in this last species the two columellar 

 lamellae are almost united with one another and usually the 

 lower one is stronger than the upper. In the var. isseli the 

 two columellars are quite distinct, and the upper is especially 

 more developed than the lower (Caziot). 



Alpes-Maritimes : Vallee de la Roya, between 1500 and 2000 

 meters (Issel). 



Series of A. variabilis. 



Slender, somewhat fusiform species, in which the lower 

 palatal plica emerges strongly, that above it weakly or im- 

 mersed. Alpic. 



39. ABIDA VARIABILIS (Drap.). PL 45, figs. 11, 12. 



The shell is obliquely rimate, lengthened-fusiform, some- 

 what transparent brownish-corneous, almost smooth; earlier 

 whorls convex, the later ones but slightly so, last whorl more 

 or less completely encircled with whitish spiral lines. Aper- 

 ture with 4 lamellae and 4 plicae : angular lamella short, some- 

 what thickened at the junction with outer lip ; deep within, a 

 short spiral lamella may usually be seen, but its presence is 

 variable ; parietal lamella entering to the dorsal side. Colu- 

 mellar and subcolumellar lamellae equal, but the former enters 

 further. Upper palatal plica short, immersed, remote from 

 the lip; interpalatal weakly reaching the lip (or interrupted, 

 immersed) ; lower palatal stronger, emerging to the lip. 

 Basal plica short, deeply immersed, but sometimes having a 

 weak continuation to the peristome. All of the plicae are 

 strongest within the dorsal wall, and are continued further 

 inward as delicate threads, varying in length. The peristome 

 is white, expanded and a little reflected, strongly thickened 

 within except near the posterior angle. 



Length 10.3, diam. 3.2 mm.; 10 whorls (Lyons). 



Length 11.5, diam. 3.4 mm.; 10% whorls (Lyons). 



