Jurassic Mullusca Jrom Arabia. 23 



Katiol gioup, although according to Waagen it seems to pass 

 up into the Oomia group. 



Compared with Belemnites tanganensisj which Futterer * 

 described from Tanga, in German East Africa, from rocks o£ 

 Oxfordian age, the Arabian specimen appears to have 

 belonged to a stouter and relatively more elongated guard, 

 with a narrower ventral groove than that species, and similar 

 differences are recognizable on comparison with the Belemnite 

 fragments described by the present writer f from Bihin in 

 Somaliland. 



Loc. The specimen is labelled " Nobat," indicating, as 

 stated by Major Hazelgrove in his letter accompanying the 

 collection, that it was found about 7 miles from that place, at 

 the end of a long valley which runs due north from Nobat 

 Dakim. It is to be observed, however, that its mode of 

 preservation is unlike that of the rest of the fossils similarly 

 labelled, and that some fragments of matrix adhering to tlie 

 specimen are identical with the matrix of the fossils from 

 the N.E. of Dihala, and differ entirely from the matrix of tlie 

 other Nobat specimens. 



Conclusions. 



From the foregoing descriptions it will be seen that these 

 Arabian Jurassic Cephalopoda are allied, on the one hand, to 

 such forms as occur in the Katrol Group of Cutch, the Upper 

 Jurassic rocks of Niti and Spiti in the Himalaya, and the 

 Upper Jurassic rocks of Somaliland ; and, on the other hand, 

 to forms occurring in the zone of Opjyeh'a tenuilobata in 

 Central Europe. 



The Katrol Group in Cutch consists of two parts. Ac- 

 cording to Waagen J the lower portion — the Kuntkote Sand- 

 stone — is the equivalent of the Upper Oxfordian beds of 

 Central Europe, and probably represents the zones of Pelto- 

 ceras himammatum above and of Peltoceras transversarium 

 below. The upper part — the Katrol sandstone and shales — 

 comprises a complex group of strata several hundred feet 

 in thickness, and may therefore, as Waagen pointed out, 

 represent more than one palseontological horizon. The Katrol 

 sandstone is well marked off both from the beds above as well 

 as from the beds below, for, according to Waagen, only one 



* K. Futterer, Zeitschr. Deutsch. geol. Gesell. Bd. xlvi. (1894) p. 30, 

 pi. V. tigs. 2, '2a-c, 3, 3fl-c. 



t G. C. Crick, Geol. Mag. [4] vol. iii. (1896) pp. 296-8. 



X W. Waagen, ' Jurassic Fauua of Kutcli,' vol. i. The Cephalopoda, 

 lutroduction aud pp. 230-232. 



