442 R. Bnlleti Newton — An EcJiinoid from Sinai. 



At a later date, M. Cotteau ' recognized this Echinoid as occurring 

 in the Turonian rocks of Algeria under the name of Linthia ohlonga. 

 On this occasion a change in the generic title was effected, without, 

 however, any explanation being given by the author. This change 

 was obviously necessary on gi-ounds of priority, since Desor's Linthia 

 of 1853 (Actes Soc. HelvL'tiqi(e,\o\. xxxviu, p. 27S) was synonymous 

 with Feriaster, founded by d'Orbigny in 1856. 



During the year 1899 M. Fourtau - published a revision of the 

 J*\)ssil Echinoids of Egypt, containing a reference to LiiUhin oblonga. 

 liesides quoting its occurrence in Algeria, he stated that the species 

 was common in the neighbourhood of Angoulcme, France, where 

 it had been found at the base of tlie Angoumian deposits, and was 

 consequently Upper Turonian. Moreover, M. Fourtau furnished 

 a remark on the original locality given by d'Orbigny which is of 

 interest to reproduce here : " Je ne connais point de Gebel Garebe, 

 pres de Suez, seule une petite eminence au pied de I'Abou Darague^ 

 porte le nom de Kroueba, e'est peut-etre lil que Lefebvre I'a 

 recoltee a moins que ce ne soit dans les couches qui bordent le 

 massif central granitique du Gebel Garib a 220 kilometres au sud 

 de Suez sur les cotes de la mer Kouge, entre cette montagne et 

 Gebel Zeit." 



As this appears to embrace all the important references to Linthia 

 ohiougn, we will now attempt to solve the position of the original 

 locality as given by d'Orbigny. According to his account M. Lefebvre 

 collected the species at " Rlont Garebe, pres Suez," a spot which 

 appears to be unknown to M. Fourtau. An examination of the 

 map, however, demonstrates that there is an eminence called Jebel 

 Gharbi or Gharabi in a slightly south-easterly direction from Suez, 

 Avhich is in the neighbourhood of Wadi Budra, overlooking the 

 Ramleh plain of Sinai. Although the specimens could not have 

 been obtained from Jebel Gharbi itself, that being of granitic 

 structure, it is quite possible that Lefebvre collected his material 

 at Jebel Dhalal, which is in the vicinity, and where Mr. Thomas 

 Barron knows the Cenomanian rocks to be present. Some of the 

 best specimens of Linthia ohlonga in the collection of the Geological 

 Survey of Egypt have been obtained at Wadi Budra, as were 

 Duncan's in previous years. This area of Sinai may therefore be 

 regarded as the special habitat of the species, rather than those 

 localities situated in the Eastern Desert of Egypt bordering the 

 Gulf of Suez and the Red Sea, as suggested by M. Fourtau. 



The Turonian age of Linthia oblonga as determined, at any rate, 

 for the Sinai occurrence by d'Orbigny, is not now accepted, more 

 especially as that author described JLemiaster cuhiciis and Clavaster 



' Cotteau, Perou, & Gautliiei* : " Ecliiuides Foss. Algerie," vol. ii (1879), fasc. 6, 

 p 75 (no figui-e given). , , 



, ~ Foui'tau, E., "Revision des Echiuides Fossiles de I'Egypte " : Mem. lustit. 

 Egyptian, vol. iii (1899), fasc. 8, pp. 631, 632. 



^ These place-names, which are difficult to find on ordinary maps of the district, 

 Avill he found in an excellent topographical map accompanying M. Fourtau's paper, 

 " Voyage dans la Partie Septentrionale du Desert Arabique " : Bull. Soc. Khediviale 

 Geographic (Caire), 1900, ser. v, No. 9, p. 576. 



