On Cretaceous Cephalopoda from Zululand. 293 



thicker, having a more obtuse sinus on the periphery, and a coarser 

 costation. Its dimensions are : 



Diameter . .135 mm. 



Thickness . . 100 ,, (74 per cent, of the diameter). 



The whorl-shape agrees with that of the type-figure in Pictet and 



Campiche, and is more rounded than that of N. pseud 'o-elega us, 



d'Orbigny, or those of the three forms of Cymatoceras described below. 



Locality. Middle Branch, Manuan Creek. Coll. W. J. Wybergh. 



18. CYMATOCERAS, sp. ind. 



One example of Cymatoceras (No. 4987) differs from the above 

 forms of the manuanense-albense group in having a flattened periphery, 

 but it agrees with some of the fragmentary co-types of C. mantianense, 

 Crick sp. These differences in whorl-shape are not important ; and 

 since the present example is somewhat fragmentary, a definite identi- 

 fication is impossible. The last septum is shown at a diameter of 

 about 90 mm., followed by a portion of the body-chamber. 



The smooth earlier whorls, in addition to the flattened periphery, 

 separate it from the holotype of C. manuanense, and the finer, 

 dichotomous costation also from C. albense. The example agrees with 

 C. pseudo-elegans, d'Orbiguy sp., in ornamentation, dorsoceiitran 

 position of the siphuucle and flattened periphery, but is not quite so 

 depressed. C. Icossmati, Spengler sp.,* has a narrower whorl- section. 



Locality. Middle Branch, Manuan Creek. Coll. W. J. Wybergh. 



19. CYMATOCERAS, sp. nov ? iud. 

 1907. Nautilus sp., Crick, loc. cit., p. 244. 



Among five specimens of Cymatoceras, referred to by Crick as repre- 

 senting "a large species which, in external characters, differs from 

 N. manuanensis chiefly in having flatter sides and a more broadly- 

 rounded periphery," four are comparable with the various forms 

 of the 'manuanense group described above, but are not well enough 

 preserved for definite identification. On the other hand, one example 

 (No. C18291) agi'ees in its squarish whorl-shape and fine ornamenta- 

 tion with a large specimen in the present collection (No. 2589) that 

 has the following dimensions : 



Diameter . 190 mm. 



Thickness . . 125 (66 per cent, of the diameter). 

 The ratio of diameter to thickness, about 3 : 2, corresponds with 



* Loc. cit. (1910), p. 129 (= N. pseudo-elegans, Blanford, non d'Orbigny). 



