4 Messrs. E. B. Newton and G. C. Crick on some 



studied, and this time by the late Dr. H. F. Blanford, who 

 recognized in part an Upper Oolitic character of the species, 

 which he considered were identical with, or closely allied to, 

 forms characteristic of the Oxford Clay. 



Dr. Oppel was the next student of this fauna, especially in 

 connection with the Cephalopoda. He noted Ammonites 

 macrocephalus as one of the characteristic species, and he 

 therefore regarded the beds as of Callovian age and equivalent 

 to the Kelloways-rock series of Europe. 



Then followed Dr. Stoliczka's memoir *, dealing in part with 

 the same subject, in which is enumerated the characteristic 

 fossils of the Spiti Shales, with some remarks as to their 

 horizonal value, as follows :— u The characteristic fossils are 

 Ammonites macrocephalus, parkinsoni, curvicosta, liparus, 

 triplicaius, and biplex ; Astarte major and unilateralis, Nu- 

 cula cuneiformis, Trigonia costata, &c. 



" Without entering at present on the questions of separate 

 zones, I believe the best equivalent of these beds is Quen- 

 stedt's Brown Jura, or now usually called Dogger, comprising 

 a great number of so-called formations, clays, limestones, 

 sandstones, shales, &c, which have in England, France, 

 Germany, &c. only local value. The Himalayan Jura 

 approaches in many respects in the character of its fossils to 

 the Russian. It is a mistaken opinion to regard certain beds 

 which contain Planulati-Ammonites as Upper Jura. The 

 Spiti Shales have been treated in this manner because they 

 abound in ' Planulati.' 1 But all those we do find, Ammo- 

 nites curvicosta, hraikenridgii, triplicatus, and the Kimeridgian 

 form of Am. biplex, all these species are not Upper but 

 Middle Jurassic; even if we could abstract all the rest of the 

 fossils. Trigonia costata proves nothing, as it goes through 

 many strata without essential alteration ; similarly the 

 Avicula ino?quioalvis. The Cutch Deposits are equally not of 

 Upper but of Middle Jurassic age, and have a great number 

 of species identical with the Oolite inferieur of Bayeux and 

 Montreuil Bellay." 



These early determinations of the Spiti fossils have been 

 subjected to considerable revision in recent years, and 

 especially so in connection with the Cephalopoda, which have 

 been more closely studied than the other groups of Mollusca. 



The latest published views as to the age of the Spiti Shales 

 appear in a monograph by Dr. Carl Diener on the geology of 

 the Central Himalayan region, where the lower beds containing 

 Belemnites gerardi are regarded as Upper Jurassic and 



* Stoliczka, Mem. Geol. Surv. India. ]86o, vol. v. part 1, p. 139. 



