22 Messrs. R. B. Newton and G. C. Crick on some 



whilst in a specimen figured also by de Loriol * from the 

 Upper Rauracian of the Bernese Jura the groove extends over 

 about one-half the length of the guard. Further, there are 

 differences in the amount of tapering of the anterior part of 

 the guard, none of the examples mentioned above tapering 

 so rapidly as Etallon's type-specimen. Belemnites astartinus 

 does not appear to have usually attained such a large size as 

 the Arabian fossil, the only figured example of that species 

 at all comparable with the present specimen being that figured 

 by de Loriol from the zone of Ammonites tenuilobatus at 

 Oberbuchsitten (Soleure), but that tapers anteriorly more 

 rapidly and has a considerably shorter groove. 



It is neither so fusiform, so depressed, nor so widely grooved 

 as the example figured by Quenstedt (' Die Cephalopoden,' 

 1849, pi. xxix. figs. Ha-c) as Belemnites hastatus depressus 

 (^Belemnites calloviensis , Oppel t)- Compared with the 

 form figured as Belemnites subhastatus by Waagen from the 

 Jurassic rocks of Catch, in which species Waagen includes 

 the Cutch specimen figured by J. de C. Sowerby \ as Belem- 

 nites canaliculains ?, and afterwards renamed by d'Orbigny § 

 Belemnites grantanus, the Arabian specimen appears to be 

 part of a more elongated guard and to have possessed a 

 much narrower ventral groove. Waagen || records Belem- 

 nites subhastatus as being not very common in the Cutch 

 Jura, where it is apparently restricted to the beds with 

 Macrocephalites macrocephalus. 



The Arabian specimen is more depressed, more hastate, and 

 provided with a narrower ventral groove than Waagen's 

 Belemnites kuntkotensis^, which, according to that author, 

 ranges in Cutch through the Katrol and Uomia groups, or, 

 in other words, from the Upper Oxford to about Lower 

 Tithonian beds ; whilst it appears to have been more elon- 

 gated and more depressed than that author's Belemnites 

 katrolensis**, a species which in Cutch is characteristic of the 



* P. de Loriol, Etude sur les mollusques du rauracien supdrieur du 

 Jura Bernois, Suppl. 1, 1895 (Mem. Soc. Pal. Suisse, vol. xxii.), p. 5, 

 pi. i. fig. 1. 



t A. Oppel, ' Die Juraformation,' 1856-8, p. 646 (1857). See also W. 

 Waagen, Jurassic Fauna of Kutch (Pal. Indica), vol. i. The Cephalo- 

 poda, pt. 1, 1873, p. 14, pi. ii. figs. 4a-d. 



% J. de C. Sowerbv, Trans. Geol. Soc. [2] vol. v. pt. 2, 1840, pi. xxiii. 

 fig. 2 & expl. 



§ A. d'Orbigny, Prod, de Paldont. 1850, vol. i. p. 326. 



|| W. AVaagen, Jurassic Fauna of Kutch (Pal. Indica), toI. i. The 

 Cephalopoda, pt. 1, 1873, p. 15. 



% W. Waagen, ibid. pt. 1, 1873, p. 3, pi. i. furs. 3 a-f. 

 ** W. Waagen, ibid. pt. 1, 1873, p. 7, pi. ii. figs. 7, 8, 9. 



