R. BiiUen Newton — Miocene Shells from Egypt. 209 



striations, which become more remote and lamellar near the 

 margin. 



Dimensions (of best specimen). — Height and length, 50 mm. 



Eemarks. — In adopting a subgeneric name, it may be 

 mentioned that Sacco recognizes this shell under j^qmpecten of 

 Paul Fischer, on account of its similarity to the type, P. opercularis. 

 It is indeed difficult to separate P. Malvince from the LinnEean 

 species, except that it is somewhat less circular and fan-shaped. 

 Hoernes' work must be referred to for a longer synonymy of the 

 species than is here offered. 



Horizon — Miocene (Tortonian). 



Distribution. — Poland ; Vienna Basin ; Touraine ; Italy ; Persia 

 (Fuchs). Egypt: Jebel Geneffe (Fuchs) ; no locality recorded 

 for the present Egyptian specimens. Coll. Geol. Surv. Egypt, 

 No. 624, Box No. 22a. 



PECTEN (^QUIPECTEN) ZITTELI, Fuchs. 

 Pecten Zitteli, Fuchs: Palseontographica, vol. xzx (1883), p. 41 (23), pi. -vii (ii), 



figs. 1-12. 

 JEquipecten Zitteli, Sacco : Moll. Terz. Piemonte, etc., 1897, pt. xxiv, p. 31. 



Description. — Shell suborbicular, furnished with 13-15 broad, 

 radial costge, and a series of corresponding deep grooves ; 

 ribs elevated and subdivided into minor grooves and ridges ; 

 ornamentation closely lamellose. 



Dimensions (of one valve). — Height, 48 mm.; length, 48 mm; 

 diameter, 10 mm. 



Eemarks. — This species belongs to the group of Pecten opercularis 

 which Fischer has named ^quipecten, and is related to P. Malvince 

 and P. cavarium of Fontannes. The Egyptian examples are in 

 a good state of preservation. 



Horizon. — Miocene (Helvetian). 



Distribution. — Egypt: Oasis Siwa (Fuchs); Camp 19. Coll. 

 Geol. Surv. Egypt, No. 371, Box No. 25a. 



PECTEX (AMUSSIOPECTEN) BURDIGALENSIS, Lamarck. 

 Fecten Burdigalensis, Lamarck : Anuales Museum, vol. viii (1806), p. 355. Hoerues, 

 " Foss. Moll. Tert.-Beck. Wien " : Abhandl. k. k. geol. Eeichs., vol. iv (1867), 

 p. 418, pi. Ixv. Fuchs : Denk. Akad. Wiss. (Wien), vol. xxxviii (1878), pt. 2, 

 p. 37. 

 Amussiopecten Burdigalensis , Sacco : Moll. Terz. Piemonte, etc., 1897, pt. xxiv, 

 p. 53, pi. XV, figs. 1-7. 

 Description. — Species of suborbicular shape, with the lower 

 valve more convex than the other ; auricles small and of equal 

 size ; valves ornamented externally with 12-14 distant, broad, 

 slightly elevated, radial costas, which are crossed by extremely 

 fine and closely-set concentric striations. 



Eemarks. — The Egyptian specimens, although somewhat imper- 

 fect, may be readily recognized as this large and well-known species. 

 Dimensions. — Height, 80 mm. ; length, 85 mm. ; diameter (both 

 valves in contact), 20 mm. 



Sacco's name of Amussiopecten was founded to include rather 

 large, but graceful, pectinoid shells, bearing internal costse and 



DECADE IV. VOL. VI. — ^NO. V. 14 



