2<i Messrs. K. B. Newton and ( }. 0. Trick on some 



1842. Belemnites hastatus (pars), Blainville ; A. D. d'Orbigny, Pal. 



Fran?., Terr, jurass. vol. i. p. 121, pi. xviii. 

 1818. Belemnites seynihastatus rotundus, F. A. Quenstedt, Cephalo- 



poden, p. 440, pi. xxix. fig. 8. 

 1857. Belemnites hastatus, Blainville ; A. Oppel, Juraformation, p. 546. 

 1870. Belemnites hastatus, Blainville ; J. Phillips, Brit. Belemnitidse 



(Mon. Pal. Soc), pt. 5, p. Ill, pi. xxviii. figs. 67-70. 

 1873. Belemnites cf. hastatus, Blainville ; W. Waagen, Jurassic Fauna 



of Kutch, vol. i. Cephalopoda, pt. 1, p. 11. 

 1876. Belemnites hastatus, Blainville ; E. Favre, Description des 



Fossiles du terrain oxfordien des Alpes Fribourgeoises (MtSni. Soc. 



Pal. Suisse, vol. iii.), p. 17, pi. i. figs. 1 a, b, c, 2, 3. 



This genus is represented by a single specimen, apparently 

 a portion of the posterior part of the guard. The fragment is 

 feebly depressed and slightly hastate ; it is truncated at each 

 end, and at the anterior end there is no indication of the 

 alveolus. The specimen is 64 mm. long; the ventro-dorsal 

 and transverse diameters of the anterior end are 11 mm. and 

 12'75 mm. respectively, the corresponding diameters of the 

 posterior end being 11 mm. and 12 mm. respectively. The 

 dorsal and ventral surfaces are nearly parallel throughout the 

 greater part of the length of the specimen, and it is only at a 

 short distance from the posterior end of the fossil that they 

 show any tendency to converge. In either a dorsal or ventral 

 aspect the specimen is feebly hastate, and has its greatest 

 width (15 mm.) at about 22 mm. from the posterior end. A 

 ventral groove extends over the whole length of the specimen, 

 being sharply denned at the anterior end and becoming wider 

 and shallower towards the posterior extremity; the dorso- 

 lateral area is slightly flattened and exhibits somewhat 

 obscurely two dorso-lateral lines. The fossil seems to have 

 formed part of a rather elongated guard, since it exhibits no 

 trace of the alveolus at its anterior end. 



The fossil appears to belong to the Hastati-gvoup ( = Hibo- 

 lithes, Montfort *), and to be nearly allied to Belemnites 

 hastatus f, but the guard is less fusiform and the ventral 

 groove reached nearer the apex than in most examples of that 

 species. But the extent of the ventral groove varies in 

 examples which have been referred to this species. Thus 

 Favre % has referred to this species an example from the 

 Oxfordian of the Alps of Fribourg in which the ventral groove 



* D. de Montfort, Conchyl. Syst. vol. i. 1808, p. 386. Zittel includes 

 this section in Belemnopsis, Bayle, which he regards as a subgenus of 

 Belemnites (Grundziige d. Palaeont. 1895, p. 441 ; 2^ Aufl. 1903, p. 475). 



f D. de Montfort, he. cit. See also H. D. de Blainville, M6m. sur les 

 Belemn. 1827, p. 71, pi. i. fig. 4, pi. ii. fig. 4, pi. v. fig. 3. 



\ E. Favre, Description des fossiles du terrain oxfordien des Alpes 

 Fribourgeoises (M6m. Soc. Pal. Suisse, vol. iii. 1876), pi. i. figs. 1 a, b, c. 



