THE NAUTILUS. 127 



The shell is small, obovate, with a very prominent, almost bulbous, 

 apex, which is radiaJly striate and decidedly more excentric than in 

 F. pallaryi , the anterior slope is very convex and the posterior 

 slope is nearly straight below the depression beneath the projecting 

 apex ; the lateral slopes are steeper and less oblique than in pallaryi^ 

 Compared with the none-septate form of Gundlachia Vhotelleriei it is 

 larger, more decidedly obovate, higher, with a more convex anterior 

 slope and the apex is much more prominent. A* clessinianus is en- 

 tirely different in its shape and proportions. The specimen I have 

 figured measures: length 3, width 2, alt. 1 mm. 



A small set from Ismailia, which I think belong to this species^ 

 are all very much laterally compressed and are proportionally higher 

 than the typical form. A characteristic example measures 3.25 xl. 75 

 x 1.5 mm. This peculiarity is probably the result of some unusual 

 environmental conditions. A similar instance in Ferrissia parallela 

 Hald. was figured by me several years ago, (1904, p. 77, pi. V, figs. 

 4-6). 



FERRISSIA CLESSINIANA (Jickeli). PI. figs. 9-11. 



1882. Ancylus clessinianus Jickeli, Jahrb. Deutsch. Mai. Ges., p. 

 366. 



1909. Ancylus isseh Pallary, Mem. Inst. Egypt., VI, p. 60, pL 

 IV, fig. 11. 



According to Pallary the types of this species were sent by the 

 collector, L'hotellerie, to Clessin under the MSS. name of A. Chotel- 

 leriei Bgt. But it is quite different from the shells that Bourguignat 

 had in his collection under that name. Jickeli did not figure his 

 species, but his description agrees exactly with specimens that I 

 have referred to it and there seems to be no reasonable doubt as to 

 the identification. The example figured is the shell figured by 

 Pallary as A. isseli and is in his collection. It measures: length 

 4.25, width 2.33, alt. 1.25 mm. 



The species is larger than any of the associated species of the Nile 

 fauna and entirely different in shape, which in a general way recalls 

 that of the American A. parallelus Hald. 



FERRISSIA PALLARYI n. sp. PI. VII, figs. 12-14. 



Shell small, subdepressed, rather broadly ovate, the left margin 

 more curved than the right ; anterior and posterior margins regularly 



