L. F. Si')ath — Jurassic Amtnonites from East Africa. 361 



Bajocian. On the other hand, it is probable that its record from the 

 macrocephalus or even later beds (by several authors) was based on 

 the occurrence of similar forms, which are, as yet, undescribed. 



Phylloceras aff. Kudernatschi and Ph. cf. disputahile confirm the 

 Bathonian age, though the latter species has been called " in- 

 different 'V and like Phylloceras mediterranemn Neumayr, probably 

 includes a variety of more or less closely related forms of its group. 

 Both Ph. Kudernatschi and Ph. disputahilehave heeniecoxded from 

 younger beds, but also from the Bajocian. Phylloceras Kunthi has 

 been found in the lower Bathonian, but is a species belonging to the 

 zone of Macrocephcdifes macrocephalus. In India and the Caucasus 

 ammonites, even from the athleta beds, have been referred to this 

 species. 



The genera Sowerhyceras and Hecticoceras already occur in the 

 Bathonian, but are typically Callovian and range into higher beds. 

 Arranged according to their localities. Ph. cf. disputahile and 

 Sowerhyceras sp. afi. tortisulcato have been found together in the 

 " grey, otherwise unfossiliferous limestone ", and Phylloceras aff. 

 Kunthi, Protetragonites cf. tripartitum, and Hecticoceras sp. juv. 

 were also collected in one bed at the Pipe-line Crossing, Mwachi 

 River. Ph. cf. Kudernatschi is recorded from a different locality, 

 and Phylloceras sp. ind. also was found by itself, west of the Mwachi 

 River. The specimens, therefore, that might suggest a post- 

 Bathonian age, namely Sowerhyceras and Hecticoceras, occur in each 

 of the two former localities associated with ammonites referred to 

 Bathonian forms, and a Bathonian age thus seems most appropriate 

 to the fauna. 



As regards distribution (apart from the European occurrences 

 mentioned under the specific descriptions, and the doubtful record 

 of Phylloceras cf. Kunthi from India), Phylloceras dis2mtahile has 

 been fojmd in India and East Africa, but the ammonites referred 

 to this species probably are not specifically identical with the 

 specimen here recorded. None of the other Phylloceras and Lytoceras 

 described from the Jurassic of Kutch belong to the types represented 

 in Professor Gregory's collection. From Madagascar also (the 

 " Callovian " beds of which Dacque considers to be the equivalent 

 of his macrocephalus zone of Pendambili) only. Phylloceras 

 mediterraneum,,'^ or a local variant, has been recorded. The latter, 

 together with Phylloceras Feddeni Waagen and M acrocepjhalites 

 also occurs in the Iron Oolite of Tanga in East Africa, but the fauna 

 described in the present paper differs from all these in having the 

 group of Phylloceras hetero-phyllum represented, and probably by 

 no less than three different forms. 



The lower Bathonian, with a more or less neritic facies, is well 

 developed in the whole of East Africa, but apparently only 



1 Till, op. cit., 1910, i, p. 185. 



? Also recorded by Suess {Das Antlitz der Erde) from Zanzibar. 



