634 ME. R. B. NEWTON ON [Nov. 191 I, 



Pliocene strata. In contour it presents generally an oblique 

 appearance, bearing some fifteen radial costae divided by well- 

 pronounced sulcations, which are furnished with a squamose-denti- 

 culate surface. The valves generally have about the same dimensions 

 each way, one showing a measurement of 33 mm. in length and 

 height. 



Occurrence. — In a grey marly-looking matrix, associated with 

 good examples of Operculina. 



Localities. — Ain Sciahat, above camp ; Ain Sciahat, Tombs of 

 Cyrene ( = Weld-Blundell Collection, British Museum). 



^Equipecten hatjeri (Michelotti). (PI. XLIV, fig. 6.) 



Pecten magnificns Michelotti, Ann. Sci. Inst. Lombardo-Veneto, 1839, vol. ix, 



p. 127, non G. B. Sowerby, 1835. 

 Pecten haueri Michelotti, ' Descr. Foss. Terr. Miocenes Italie Septent.' 1847, 



pi. iii, fig. 13 & p. 88. 

 JEquipecten haueri Sacco, ' Moll. Terr. Terz. Piemonte ' 1897, pt. 24, pi. vii, 



figs. 1-10 & p. 22. 

 Pecten haueri Oppenheim, Zeitschr. Deutsch. Geol. Gesellsch. 1903, vol. lv, 



pi. viii, fig. 5 & p. 154. 



Remarks. — Referred to this species is a fragmentary valve, with 

 obscure remains of auricles, but which in sculptural characters and 

 general contour appears to completely agree with this form of 

 pectinoid shell. 



The greater part of the umbonal surface is preserved, together 

 with a few of the costae on the left side of the specimen, otherwise 

 the remainder is stripped of its test and appears as an internal cast. 

 About eighteen costae can be counted, which are fine and well 

 rounded in the umbonal area, but afterwards become flattened and 

 spreading, especially at the flanks. The early ribs are micro- 

 scopically and closely imbricated. The great feature of the shell, 

 however, concerns the numerous close radial lines made up of 

 microscopical granulations which give a divided or tripartite cha- 

 racter to the costae as well as decorating the intermediate sulcations. 

 Distant concentric striations are also present. 



Dimensions (approximate) . — Len gth = 65 millimetres ; height = 

 55 mm. 



This species was originally described from ^Northern Italy in 

 beds now regarded as of Helvetian age ; in recent years Dr. Oppen- 

 heim has recognized it as part of the ' Schioschichten ' fauna, and 

 consequently as belonging to the Aquitanian horizon. 



Occurrence. — In a cream-coloured limestone with minute black 

 specks of mineral matter, and externally weathering to the usual 

 reddish-brown ferruginous colour ; it contains Operculina. 



Locality. — Birlibah. 



Oopecten rotundatijs (Lamarck). (PI. XLIY, fig. 3.) 



Pecten rotundatus Lamarck, ' Hist. Nat. Anim. sans Vert.' 1819, vol. vi, pt. 1, 

 p 179 • Deshayes, 2nd ed. of same work, 1836, vol. vii, p. 156 ; Fuchs, 

 Denkschr. K. Akad. Wissensch. Wien, 1879, vol. xli, pt, 2, pi. ii, tigs. 1-2 & 

 p. 104 ; Fontannes, ' Etudes Stratigr. Paleont. Periode Tert. Bassin du 

 Rhone : le Bassin de Crest ' 1880, vol. vi, pi. v, fig. 1 & p. 161. 



