WHITEAVES.] FOSSILS OP TEIASSIC KOCKS OP BRITISH COLUMBIA. 145 



very unusual combination of characteristics. I propose for this group 

 the name Dorikranites (from Aopinpavog, spear-headed), the type 

 being DorUcranites Bogdoanus (=Balatonite8 Bogdoanus, Mojsis., Ceph. 

 der Triaspr., p. 87, pi. 80, figs. 1-4), and the following were described 

 by Mojsisovics under the name of Balatonites, Dorikranites rossicum and 

 D. acutum. 



The young of Arniotites has a thin keel, and this, together with the 

 form of the whorls and pilfE, shows that the more discoidal and stouter 

 shells of Oeltites are larval or radical foi'ras as compared with Arniotites, 

 and are probably the near allies of this series. In Arniotites the earliest 

 whorls are often smooth, compressed, and are probably rounded as well 

 as keel-less on the abdomen.* The shell during this stage must have 

 closely resembled the adult of Dinarites Mohamedanus, Mojsisovics 

 (Mediterr. Triaspr., p. T, pi. 40), and more I'emotely Ceratites Sturi 

 (ibid, p. 44, pi. 39), both of these being forms belonging to the direct 

 line or stock of Ammonoid radicals which terminate^ in the Lias with 

 Psiloceras planorbe. Among Balatonitidaj, Arniotites, with its smooth 

 young, evidently bore precisely similar relations to those stock radi- 

 cals of the Trias that Arnioceras, among the Arietidse, bore to the stock 

 radical, Psiloceras, in the Lias. Arniotites Vancouverensis, Whiteaves, 

 does not approximate closely to any species described by Mojsisovics. 

 The pilffi are straighter, the forward bend is hardly perceptible, the 

 whoi'ls are narrower, and the young smooth for a more prolonged 

 period of the growth. These characters have all been exaggerated by 

 compression, but this cannot account for the whole of the observable 

 dilferences. This species is, of course, the type of the genus, and the 

 small specimen from Crescent Inlet shews the characters best. The 

 following species are described and figured by Mojsisovics in his great 

 work (Ceph. der Mediterr. Ti'iaspr.) under the name Balatonites; 

 Arniotites euryomphalus, A. arietiformis, A. prezzanus, A. stradanus and 

 A. Meneghini. 



* " It is quite common for species of Ammonoids to be rounded and keel-less on the abdomen, 

 during the smooth stage, until the shell is of considerable size, and they are invariably so during 

 the earlier part of the smooth stage. The slight crenulations of the keel, described by Mojsiso- 

 vics in Balatonites arietiformes, are probably not constant in all the species and I have not 

 considered them as of generic importance." 



