Jurassic Molluscd from Arabia. 19 



coarse ribs, showing a definite bifurcation on the lateral 

 area into two equally coarse ribs which pass without inter- 

 ruption over the peripheral area. Unfortunately the specimen 

 is so imperfect that it does not exhibit the whole height of 

 the whorl, and it is so crushed that it does not show the 

 original shape of the transverse section of the whorl. The 

 ornaments appear to be relatively coarser than those of the 

 other examples of Perisphinctes in the collection ; the cha- 

 racter of the bifurcation of the ribs is also slightly different, 

 there being in this fragment a slight thickening at the point 

 of bifurcation. The ribbing, in fact, agrees very closely with 

 that of the earliest portion of the outer whorl of Sowerby's 

 type specimen of Perisphinctes pottingeri, with which we have 

 compared it. Sowerby's type specimen came from the 

 " Desert N.E. of Cutch." According to Waagen, this 

 species and the closely allied but more coarsely ornamented 

 form Perisphinctes katrolensis * are in Cutch very common 

 in the coarse iron-sandstone of the Katrol range that corre- 

 sponds to about the middle of the Katrol Group. Dr. Waagen 

 regarded the Cephalopoda of this group as corresponding to 

 those of the Kimeridgian and Upper Oxfordiau beds of 

 Europe. The group is divided into two parts, of which 

 de Lapparent regards the Lower as of Sequanian and the 

 Upper as of Kimeridgian age f. 



Loc. Valleys between the villages of Al-Kura and Samma, 

 about 15 miles N.E. of Dihala. 



Genus Oppelia, Waagen. 

 Oppelia ? sp. (PL III. fig. 4.) 



The flattened remains of a smooth minutely umbilicated 

 shell about 39 mm. in diameter are probably referable to the 

 genus Oppelia, but the fossil is too imperfect to be specifically 

 determined. 



Loc. Valleys between the villages of Al-Kura and Samma, 

 about 15 miles N.E. of Dihala. 



C. Belbmnoidea. 



Genus Belemnites, Lister. 



Belemnites cf. hastatus, H. D. de Blainville. 

 (PI. II. figs, la, b, c.) 



1827. Belemnites hastatus, H. D. de Blainville, Mem. sur les Belemn. 

 p. 71, pi. i. rig. 4, pi. ii. fig. 4, pi. v. fig. 3. 



* W. Waagen, op. cit. p. 4, 1875, p. 184, pi. liii. 



t A. de Lapparent, ' Traits de Geologie,' 5th ed. 1906, vol. ii. pp. 1243 



& 1255. 



9* 



