224 PERUSSACIA. 



narrowly rounded at the base. Peristome straight, acute, a 

 little thickened within; columella short, callous; the outer 

 margin nearly straight; margins joined by an indistinct cal- 

 lus. The shell is very glossy, smooth, transparent, of an al- 

 most uniform yellowish-corneous tint. Length 9.5, diam. 3 

 mm. (Loc.). 



Portugal. 



Ferussacia castroiana LOCARD, Conchyl. Portugaise, Coq. 

 terrest. etc., in Archives du Mus. d'Hist. Nat. de Lyon, vii, 

 1899, p. 139. 



Distinguished chiefly by its regularly cylindric shape, taper- 

 ing abruptly at the two ends. The increase of the whorls is 

 very slow and very regular to the last whorl, where it is very 

 rapid. The aperture is four-ninths the total length. 



4. F. AMBLYA Bourguignat. PL 41, figs. 59, 60. 



This Ferussacia is distinguished from amauronia and for- 

 besi by its short, swollen form, regular and rapid convolution 

 of the whorls of the spire, larger aperture, the columella more 

 calloused and shorter. Length 8.5, diam. 4, aperture 4 mm. 

 (Bgt.). 



Around Algiers and other localities in Algeria. 



Ferussacia amblya BGT., Malac. chat, d'lf, pi. 2, f. 17-19 

 (1860) ; Malac. de 1'Algerie i, p. 40, pi. 3, f. 13-15. 



The specimen before me looks like a short form of F. folli- 

 culus. The following species is evidently quite similar. 



5. F. GRAVIDA Florence. 



Shell oblong, relatively short, ventricose, the greatest thick- 

 ness at the upper part of the last whorl, slightly tapering 

 downwards, fragile, diaphanous, very glossy, uniform pale 

 corneous, very smooth. Spire moderately produced, obtuse, 

 shortly tapering above and somewhat rotund, the apex ob- 

 tuse. Whorls 5i/2> irregularly increasing, the first minute, 

 next relatively large, the third minute, fourth suddenly 

 swollen and ample, the last whorl very ample and swollen 

 above. Suture linear. Last whorl half the total length, regu- 

 larly descending in front. Aperture vertical, irregularly 



