630 ME. E. E. NEWTON ON [NOV. 19II, 



The true 0. caudata belongs to the Miocene regions of Germany 

 (Goldfuss, etc.), Egypt (Oasis of Siwa) as recorded by Dr. Blancken- 

 horn, 1 and of the Marmarican plateau near Alexandria as recog- 

 nized by M. G. F. Dollfus, 2 and is regarded as of Lower Helvetian 

 age. 



Occurrence. — Matrix of a reddish-brown colour and full of 

 foraminifera (Operctilina, etc.). 



Locality. — East of the shrine of Sidi Mahomet Mahridi, east of 

 Slonta. 



Ostrea ceassicostata G. B. Sowerby. (PI. XLV, figs. 1 & 2.) 



Ostrea crassicostata G. B. Sowerby, Q. J. G. S. 1847, vol. iii, pi. xix, tig. 23 

 & p. 420 ; Hcjemes, ' Foss. Moll. Tert.-Beck. Wien ' 1870. pi. lxviii, tig. 4, 

 p. 441 ; F. A. P. da Costa, ' Moll. Tert. Portugal ' Comm. Serv. Geol. Portugal, 

 1903, p. 5. 



Ostrea excavata Oppenheim, Zeitschr. Deutseh. Geol. Gesellsch. 1903, vol. lv, 

 pp. 151-52. 



Remarks. — The best of two specimens is a fine example of 

 Sowerby's shell originally described from Portuguese Tertiary beds, 

 now regarded as of Lower Burdigalian age. 3 Only the lower valve 

 is preserved, but it is exceedingly thick and robust, exhibiting on 

 the dorsal surface the nearly equidistant and few longitudinal 

 plications so characteristic of the species. The interior possesses a 

 rnoderately excavated area, a deeply impressed anterior muscular 

 scar of large size with a concentrically banded surface, and a short 

 and broad ligamental area. 



Dimensions. — Length = 75 millimetres; height = 90 mm.; 

 thickness = 50 mm. 



According to Hcernes the species ranges from the lower beds of 

 the Horner Schichten ( = Aquitanian) to the Leithalkalk ( = Torto- 

 nian) of Vienna Basin localities ; and, as previously stated, it 

 belongs to the Lower Burdigalian deposits of Portugal and the 

 Aquitanian of Italy. 



Occurrence. — Next to no matrix is associated with these speci- 

 mens, and both have a generally reddish-brown colour ; no forami- 

 nifera are discernible. 



Localties. — East of the shrine of Sidi Mahomet Mahridi, east 

 of Slonta. The thick example comes from west of Lamludeh. 



Spondyltjs ctsalpinus Brongniart. (PI. XLIY, fig. 2.) 



Spondylus cisaljpinus A. Brongniart, ' Mem. Terr. Sed. Super. Calcareo-Trapp. 

 du Vicentin ' 1823, pi. v, figs. 1 a-\ c & p. 76 ; Fuchs, ' Beitr. Concliyl. 

 Vicentinischen Tertiargeb.' Denkschr. K. Akad. Wissensch. Wien, 1870, 

 vol. xxx, pt. 2, pi. vii, figs. 11-12 & p. 168 ; Hoernes, ' Beitr. z. Kenntn. Tert 

 Ablag. Siidalpen (Schioschiehten) ' Jahrb. K.K. Geol. Reichsanst. 1878, 

 vol. xxviii, p. 29 ; Oppenheim, Palseontographica, 1901, vol. xlvii, p. 141, and 

 Zeitschr. Deutseh. Geol. Gesellsch. 1903, vol. lv, p. 175. 



Remarks. — A single example with both valves in the closed 

 condition represents this species. It is quite a limestone specimen 



1 Zeitschr. Deutseh. Geol. Gesellsch. vol. liii (1901) p. 109. 



2 In D. E. Pachundaki's ' Contrib. Etude Geol. Marsa Matrouh (Mar- 

 marique)' Revue Internat. Egypte, vol. iv, pt. ii (1907) p. 12. 



3 See F. A. P. da Costa, op. cit. pp. 3 et seqq. 



