Vol. 67.] KA1NOZOIC MOLLUSCA PEOM CYRENAICA. 641 



System, and is known from Kressenberg and other Central 

 European localities (Belgium, France, Russia), and Egypt. The 

 Priabonian form is recognized by Lefevre l as Ovula gigantea var. 

 Jioernesi, from Northern Italy (Brendola), which chiefly seems to 

 differ in the possession of an angulated marginal summit to the 

 outer wall, although judging from the figures this is not constant, 

 as some show a well-rounded shoulder to that region ; it is, how- 

 ever, of much larger size, an adult example, according to Lefevre, 

 measuring 300 mm. in length and 200 mm. in width, whereas 

 a full-grown form of 0. gigantea is said by the same author to 

 measure 145 mm. in height and 120 mm. in width. The present 

 specimen has a very similar contour to D'Archiac's Ovula murchisoni 

 from the JNummulitic rocks of India, 2 and it is probable that that 

 species might more correctly be regarded as a synonym of Gisortia 

 gigantea. 



Occurrence. — In a cream-coloured limestone, no Nummulites 

 being distinguishable with an ordinary lens. 



Locality. — Mersa Susa. 



Vasum cf. frequens (Mayer-Eymar). (PI. XL VI, fig. 9.) 



Turbinella frequens Mayer-Eymar, Journ. Conchyl. [Paris] 1895, vol. xliii, 



pi. ii, fig. 7 & p. 47. 

 Vasum frequens Cossmann, Bull. Inst. Egyptien, 1901, ser. 4, no. 1, pi. i, fig. 7 



& p. 179. 

 Turbinella frequens Oppenheim, Palseontographica, 1906, vol. xxx, pt. 3, No. 2, 



pi. xxiv, figs. 1-7 & p. 318. 



Remarks. — This form is represented by a very rough limestone- 

 cast in which the maximum width of the summit region is greator 

 than the entire length of the shell. The earliest whorls are lost, 

 but what is preserved of the spiral region shows it to be of a 

 depressed character. The front aspect of the specimen is, however, 

 important, as it possesses a well-inflated columellar surface on 

 which can be traced three or four distant, obscure, nearly horizontal 

 plications ; the outer lip-margin is well rounded, and encloses a 

 fairly open aperture of equal width throughout. The actual base 

 is wanting, although, judging from the general contour, the canal 

 would have been short and insignificant ; the remains of a large 

 spinose tubercle are present on the periphery. 



Dimensions. — Length = 65 mm.; width (maximum) = 82 inm. 



The specimen is evidently related to Turbinella frequens, de- 

 scribed by Mayer-Eymar, which has since been well figured both 

 by M. Cossmann and Dr. Oppenheim, the latter regarding it as 

 occurring throughout the Mokattam Beds of Egypt, and even 

 doubtfully suggesting that it is found in the Nummulites-inter- 

 meclius ( = Priabonian) Beds in the neighbourhood of Siwa in the 

 same country. The species is at present restricted to Egypt. 



Occurrence. — It occurs in a yellowish limestone containing 

 Nummulites, Lithothamnion, and other organisms. 



Locality. — Camp at Messa. 



1 Ann. Soc. Malacol. Belg. vol. xiii (1878) pp. 41-42 & pis. iii, iv, vii, viii. 



2 * Descr. Animaux Foss. Nummulit. Inde ' vol. ii (1854) p. 329 & pi. xxxiii, 

 figs. 4-4 a. 





