208 R. BiiJlen Newton — Miocene Shells from Egypt. 



PECTEN CRISTATO-COSTATUS, Sacco. 

 Fecten cristato-costaUis, Sacco: Moll. Terz. Piemonte, etc., 1897, pt. xxiv, p. 64, 

 pi. xxi, figs. 1-7. 



Description. — Testa affinis P. subarcuatus, Tourn., sed in vaha 

 dextera costce radiales vaJde elntiores, strictiores, acutiores, sub- 

 triangidares, sulci's profundissimis {costis latioribus) disjunct ce. (Sacco.) 



A single lower valve from Egypt appears to belong to this 

 species, although the radial costas become rounder as they reach 

 the ventral margin, and their terminations are ornamented with 

 extremely fine transverse stride. In all other characters it is 

 extremely like Sacco's shell. Costge 18-20. 



Dimensions (of a lower valve). — Height, 40 mm. ; length, 41 mm. ; 

 diameter, 11 mm. 



Remarks. — This species is closely related to Janira benedicia 

 (Lamarck), Fontannnes, from the Pliocene of the Ehone Valley, 

 and differs mainly in possessing a greater number of ribs. 



Horizon. — Miocene (Helvetian). 



Distribution. — Italy. Egypt: Camp 19. Coll. Geol. Surv. 

 Egypt, No. 371, Box No, 25^ a. 



PECTEN ESCOFFIEE^, Fontannes. 

 Fecten Escoffierm, Fontannes : E'tudes Tert. Bassin Ebone, 1878, pt. iii, p. 95, pi. v, 

 fig. 1. Fuchs : Palseontograpliica, vol. xxx (1883), p. 24 (42), pi. viii (iii), 

 figs. 9-12. 



Description. — Shell small, subtriangular, and with a moderately 

 convex right valve, bearing about 18 subrotund, elevated costse ; 

 the sculpture consists of fine concentric striae in the grooves, which, 

 become more or less lamellar on the depressed summits of the ribs. 



Dimensions (of right valve). — Height and length, 21mm.; 

 diameter, 5 mm. 



Eemarks. — The collection contains only a right valve of this 

 species. Fuchs has already recognized it from Egyptian rocks. 



Horizon. — Miocene (Helvetian). 



Distribution. — Visan Basin (Fontannes). Egypt : Siwa (Fuchs) ; 

 Camp 22. Coll. Geol. Surv. Egypt, No. 324, Box No. 26^^ a. 



PECTEN (JEQUIPECTEN) HALVING, Bois de Montpereux. 

 Fecten Malvinrs, Bois de Montpereux: Conch. Foss. Wolhyni-Podolien, 1831, p. 71, 



pi. V, figs. 2, 3. 

 Fecten opercularis, Goldf uss : Petrefacta Germanise, yoI. ii (1833), p. 62, pi. xcv, 



figs. &a-t) {non c and d) (Lamarck, non Linnaeus). 

 Fecten Ilahmce, Hoernes, "Foss. Moll. Tert. -Beck. Wien": Abhandl. k. k. geol. 



Eeichs., vol. iv (1867), p. 414, pi. Ixiv, figs, ba, h. Fuclis : Palseontographica, 



vol. XXX (1883), p. 24 (42). 

 ^quipecten Malvince, var. acuticostulata, Sacco: Moll. Terz. Piemonte, etc., 1897, 



pt. xxiv, p. 16, pi. iii, figs. 36-40. 



Description. — Both valves of this shell are convex and circular 

 in shape, with a variable number of longitudinal costse ; the original 

 description gives 30-35, Hoernes mentions 30, whereas Fuchs 

 says that the average number is 21, which agrees best with what 

 is seen on the Egyptian specimens. The ribs ai'e simple over 

 the umbonal region, but afterwards split up into three or four 

 divisions, with minute interstitial spaces between each ; both the 

 ribs and the spaces are ornamented with lamellose and concentric 



