ORCULA. 25 



de la Greee, 1879, p. 101), but just what these authors had 

 remains uncertain. It is quite possible that critica was the 

 form now called turcica. As it was quite insufficiently de- 

 fined, the name should be dropped. Several forms with little- 

 developed columellar folds have been fully described since 

 critica was published. 



7. Orcula imbricata (Jickeli). PL 2, figs. 7, 8, 9. 



Shell rimate, obovate-cylindric, with oblique membranous 

 riblets, rather thin, brown. Spire long with obtuse apex, of 9 

 somewhat flattened whorls, imbricating below, the last one- 

 third the length. Suture deepened. Aperture rounded-oval, 

 biplicate ; one oblique high fold on the parietal wall, deeply 

 entering; one inconspicuous columellar. Peristome dilated, 

 reflected, the margins converging. Length 5, diam. 2.5; 

 aperture, alt. 2, width 1.75 mm. (Jickeli) . 



Abyssinia : Province Hamaszen, on the way from Genda to 

 Asmara, under stones (Jickeli). Senafe, Adigrat, Agula and 

 Meshek (Blanford). 



Eritrea: Agame, Adi-Guden and Monte Cherseber (Boc- 

 cardi). 



Pupa imbricata Jickeli, Malak. Bl., xx, 1872, p. 107 ; Moll. 

 nordost-Afr., in Nova Acta k. Leop.-Carol. deutschen Akad. 

 Naturforscher, Bd. 37, p. 115, pi. 5, f. 7. — Pollonera, Boll. 

 Mus. Zool. Anat. Comp. Torino, xiii, no. 313, p. 5. — Pupa n. 

 sp. near doliolum Blanford, Obs. Geol. and Zool. Abyssinia, 

 1870, p. 477, no. 15. 



This species stands very near 0. doliolum, but it differs, as 

 Jickeli pointed out, by the very convex whorls of the upper 

 part of the spire, which overhang the suture. The last whorl 

 ascends slowly but considerably, and has a well-rounded base. 

 The peristome is well reflected, white, not much thickened. 

 Parietal callus thin, with a very weak angular tubercle or 

 none. The parietal lamella emerges to the edge of the callus. 

 It is high within the last whorl, and penetrates 1% whorls 

 inward. The columella shows one or sometimes two low 

 lamellae in the mouth, becoming stronger within the back than 

 in doliolum, the lower one stronger than the upper. The 



