288 DIGONIAXIS. 



it is concave. The columella is obliquely truncate at base. 

 The outer margin of the peristome is thin and acute. Length 

 4.5, diam. 1.5, aperture 2.5 mm. (Jickeli). 



Egypt: near the Mahmudi canal at Alexandria, one dead 

 shell in a rice field. 



Ferussada unidentata JICK., Malak. Bl. xx, 1872, p. 103; 

 Fauna der Land-und Susswasser-Mollusken Nord-Ost-Afrika's, 

 in Nova Acta Acad. Caes.-Leop. Carol. Germanics Nat. Cur. 

 vol. 37, p. 132, pi. 5, f. 20, 1875. KOBELT, Iconogr. vii, p. 36. 



Differs from C. hierosolymarum by the longer last whorl and 

 narrower aperture. This species, known from a single example 

 has been referred to Calaxis with doubt by Westerlund and 

 Kobelt, but from Jickeli's remarks and comparison with the 

 type of Calaxis hierosolymarum, it seems to belong strictly to the 

 same group. 



Genus DIGONIAXIS Jousseaume. 



Digoniaxis Jouss., Bull. Soc. Malacologique de France, vi, 

 1889, p. 348, for D. bourguignati. 



Shell long, turrite, composed of numerous slowly and regu- 

 larly increasing whorls. Aperture about one-third the total 

 length, semiovate, the outer lip simple, arching forward; colu- 

 mella vertical, strongly bilamellate; internal axis spirally 

 sinuous. 



Type D. bourguignati. Distribution, Aden, Ceylon. 



A genus of uncertain position, probably near Calaxis, as M. 

 Jousseaume believes, but differing in the longer spire and the 

 strong development of a spiral lamella superposed upon the 

 upper part of the columella. There are no parietal or palatal 

 lamellae. The internal axis, as seen through the shell, is 

 strongly spiral, the upper lamella penetrating deeply, according 

 to Jousseaume. It is possible, however, that the spiral condi- 

 tion is due to the basal lamella. 



1. D. BOURQUIGNATI Jousseaume. PI. 50, figs. 1, 2. 



Shell imperforate, elongate-acuminate, very thin, translucid, 

 vitrinoid, very glossy, polished, or under a very strong lens 

 delicately striatulate. Spire long, acute at the apex. Whorls 

 10, convex, slowly increasing, separated by a deep suture; the 



