94 POMPECKJ. JURASSIC FAUNA OF CAPE FLORA. [NORW. POL. EXP. 



of the figured piece, Hie saddles are still low. Close to the seam of the 

 umbilicus, two small auxiliary lobes occur 1 . 



The corresponding fragment of the enclosed whorl is broad, low, and also 

 already somewhat coarsely ribbed. The fragment of Cadoceras Frearsi (d'Orb. 

 sp.) Nik. cast of pyrites altered to brown iron-stone - - was found loose, 

 without any adhering rock, on July 12th, 1896, near the margin of the 

 glacier, northwest of Elmwood. 



Remarks. With regard to the juvenile forms of Cadoceras Frearsi (and 

 in contradistinction to Cadoceras Elatmce) Nikitin (1885, 1. c. p. 16), stales that 

 "the ribs are more curved, and in the small volutions even somewhat falci- 

 form". In the specimen before me, the sickle form is as little perceptible as 

 in the young specimen (first determined as Cadoceras Elatmce), which Nikitin 

 figured 1881, 1. c. PI. XI. fig. 22; or in a specimen of Cadoceras Frearsi 

 before me, from the Russian Jura of Elatma (Munich Museum). 



Cadoceras sp. indet. 

 PI. II. fig. 8. 



1897. Ammonites (Macroceplialites) macrocephalus Schloth. var. E. T. New- 

 ton; E. T. Newton and J. J. H. Teall, I. c. Quart. Journ. 

 Geol. Soc. London. Vol. 53, p. 498. PI. XXXIX. fig. 3. 



The impression given in fig. 8 of PI. II belongs to the widely umbili- 

 cated juvenile form of a Cadoceras with thick whorls. The rapid increase 

 in thickness of the whorls points towards an affinity to the group of Cado- 

 ceras modiolare d'Orb. and Cadoceras Elatmce Nik., but even this cannot be 

 positively asserted. 



From the thickness of the whorls, the width of the umbilicus, and the 

 form of the sculpturing, Newton's Amm. (Macrocephalites) macrocephalus 



1 It is a characteristic of Cadoceras Frearsi (d'Orb. sp.) Nik. that the second lateral lobe 

 is pushed rather near the umbilical seam, and that for this reason the saddles and the 

 auxiliary lobes after the second lateral lobe become comparatively very small. In 

 succeeding whorls, the second lateral lobe is pushed towards the blunt upper margin 

 of the umbilicus. On this point, Cadoceras Frearsi even in its early stages, differs 

 not only from the more remote species, Cad. sublccve Sow. sp., Tchefkini d'Orb. sp., 

 Nanseni n. sp., stenolobwn (Keys.) Nik., but also from the more closely allied Cado- 

 ceras Elatmm Nik., modiolare Nik., and the other Cadocerates allied to these specie*. 



