360 L. F. SjjcUIl — Jurassic Ammonites from East Africa. 



Hecticoceras ^ rather than to other contemporaneous Oppelids. 

 It should be pointed out, however, that the East African specimen 

 might equally well represent the inner whorls of such Callovian 

 LuHidoceras as those figured by Quenstedt,"^ Waagen,^ Till,* 

 Tsytovitch, etc., or even of such Oxfordian and Argovian forms as 

 those figured by de Loriol'' and Noetling.® As has been pointed 

 out before, its affinity with the Bathonian forms of the type of 

 "Oppelia'' hisculpta OpjDel sp. =J. Henrici Kudernatsch non 

 d'Orbigny '' is suggested only by the associated ammonites. 



Hecticoceras Haugi, Popovici-Hatzeg, has a narrower umbilicus in 

 the adult, and the whorl-section, then, also differs considerably,^ 

 but the young probably comes very near to the specimen here 

 examined. On the other hand, the suture-line appears to be more 

 complex in the Roumanian specimens. 



Horizon. — Hecticoceras, comparable to the East African specimen, 

 occur in the Bathonian as well as the Callovian. 



Locality. — No. 550, Mwachi River, Pipe-line Crossing. Found 

 together with Protetragonites cf. tripartitiAs Raspail sp. and with 

 Phylloceras cf. Kunthi Neumayr. 



Conclusions. 

 The fauna described in the present paper consists, then, of the 

 following seven Ammonites : — 



Phylloceras aff. Kudernatschi Hauer. 

 ,, sp. ind. 



,, cf. Kunthi Neumayr. J 



,, cf. disputahile Zittel.^ 



Soiverhyceras sp. aff. tortisulcato d'Orbigny sp, 

 Protetragonites cf. tripartitus Raspail sp. 

 Hecticoceras sp. juv. 

 It is a matter for regret that more definite identifications could not 

 be given, but not one of the specimens represents an adult shell, 

 and three of them are fragmentary. It is one of the latter {Pro- 

 tetragonites cf. tripartitus) that has been mainly relied on in 

 determining the fauna as probably of Bathonian age ; but this 

 species already occurs in the Parkinsoni beds of the uppermost 



^ As represented by e.g. " Opj)elia " retrocostata Grossouvre (" Etudes sur 

 I'Etage Bathonien " : Bull. Soc. Geol. France, ser. in, vol. xvi, 1888, p. 374, 

 pi. iii, figs. 8, 9), and the Cornbrash species " Harpoceras " (Ludwigia) 

 mibpuncfafum (Schlippe " Fauna Bath. Oberrhein. Tiefl." : Abh. Geol. Spec. 

 K. Eh.-Lothr. vol. iv, 1888, No. 4, p. 196, pi. v, fig. 3). Haug (loc. cit., 1898, 

 p. 82) considers them identical. 



^ A7nm. Schwab. Jura, 1887, pi. Ixxxii, e.g. figs. 23 and 32. 



•■' Loc. cit., 1873, e.g. pi. xiii. 



* Loc. cit., 1910, e.g., pi. xviii (iii). 



5 Loc. cit.., 1898, e.'g. H. BonareUii, de Loriol, pi. iii, figs. 19-21, and 1900, 

 pi. iii, p. 14. 



^ Loc. cit., e.g. " Harpoceras " Guthei, Noetling, p. 20, pi. ii, figs. 6-8a, 



7 Loc. cit., 1852, pi. ii, figs. 9-13. 



8 Loc. cit., 1905, text-fig. 9 on p. 19 



