NO 2.] 



DESCRIPTION OF THE FOSSILS. 



87 



1897. Ammonites [Cadoceras) modiolaris Luid., "flattened variety". 



£. T. Newton; E. T. Newton and J. J. H. Teall, 1. 

 c. Quart. Journ. Geol. Soc. London, vol. 53, p. 497, 

 pi. XXXIX. fig. 10. 



Several young individuals with flattened body-chambers, numerous im- 

 pressions of young pieces and fragments of a larger specimen cannot be 

 identified with any of the Cadoceras species hitherto described, t call the 

 new species after the bold explorer of Franz Josef Land, and beg Prof. 

 Nansen to see in this a token of my gratitude. 



Up to a diameter of 30 mm. the Ammonite shows a flat, disc-like growth. 

 The whorls are moderately thick. In cross section they are nearly elliptical, 

 with the greatest width a little below half the height of the whorls. The 

 involution is considerable; more than the half though not quite ^/s of the 

 inner whorls are covered by the outer. 



In young specimens the umbilicus is rather narrow and not very deep. 



The sculpturing consists of closely placed rather sharp ribs, with a for- 

 ward inclination. They are either in shallow curves, or slightly falciform. 



+ a. b. 



Fig. 16. Cadoceras Nanseni n. sp. 



a. figured from a wax-cast of an impression, body cbamber compressed and broken ; nat. size. 



b. constructed diagram. 



Near the external side the ribs are somewhat more bent forward. They 

 cross the external side in a broad curve without forming any angle. With 

 regard to the first appearance of sculpturing, the mode of bifurcation of the 

 ribs (interpolation of the secondary ribs from the outside), and the irregular 

 alternation of single and divided ribs, Cadoceras Nanseni is similar to Ca- 



