TYLOSTOMA DEPEESSUM. 21 



Say Pictet and Campiche (op. cit., II, p. 352): "Le T. faUax est facile a 

 confondre avec le Natka prcebnga d'Orb., dont il a tout a fait les dimensions, 

 Tangle spiral, etc. 11 a etc souvent place sons ce nom dans Irs collections 

 et probablement cite dans les catalogues. II est du reste bien distinct, et si 

 les moules ne sont pas encroutes, on reconnait facilement le Tylostoma a son 

 ouverture etroite, bien moins oblique, aigu en arriere, et a son bord columel- 

 laire presque droit." 



Though N. prcelonga is still recognized as a distinct species by the Swiss 

 paleontologists just quoted, and by Coquand, who claims to have found in 

 Algeria both that and his species elaiior, it would not be surprising if the 

 study of fuller suites of all the above named (hitherto known only from 

 casts), together with the careful observation of their variations and distor- 

 tions, should lead to their reduction to a single species. 



Coll. .Merrill. Thomson, and Congregational House. 



Locality and Position, — Beirut district; from a yellow ferruginous marl, 

 probably identical with that of Abeih. 



? Tylostoma depressum Pictet and Campiciie. 



Plate I, fig. "I- 



Ti/losluma depressum Pictet and Campiche, 1SG2, Toss, du Terr. Cret. de Ste.-Croix, II, p. 355, 

 PL lxxiii, figs. 10, 11. 



Single internal cast, incomplete at apex, four whorls remaining. Length, 

 G3 mm., originally about TO mm.; width, 53 mm. 



This seems to be an adult specimen of the Swiss species named above, of 

 which Pictet and Campiche figure two casts of immature individuals, bearing 

 impressions of the internal varices. They represent T. depressum as being 

 distinguished -par ses proportions et par la forme de son dernier tour, qui 

 est court, deprime' a sa partie anterieure, ce qui rend la bouche courte, 

 obtuse et oblique." (loc. cit.) This description applies without qualifica- 

 tion to the Lebanon fossil. 



Coll. Congregational House. 



Locality and Position. — Probably the Beirut district; from a yellow marl, 

 apparently identical with that of Abeih. 



