On Cretaceous Cephalopoda from Zululand. 285 



9. SlTBSCHLOENBACHIA C'f. TRINODOSA, B6se Sp. 



(PI. XXV, fig. 4.) 



1910. Schloenbachia trinodosa, Bose. "Mon. G-eol. & Pal. Cerro de 

 Muleros," Bol. Inst, Geol. Mexico, No. 25, p. 78, pi. x. figs. 2-4. 



A whorl-fragment (No. 4972), about 100 mm. long, is comparable 

 with the smaller specimen figured by Bose, but has a slightly more 

 depressed whorl-section. The spiral ornamentation, also, is very well 

 preserved on this (body-chamber?) fragment, whereas the Mexican 

 original, a septate cast, does not show it. The present example is 

 distinguished from the form above described (8. prerostrata) by its 

 whorl-section, which difference results in very dissimilar ventral 

 aspects of the two species. The trituberculation also is a distinctive 

 feature of the form here described, quite different from the ornamen- 

 tation of the earlier group, with the high umbilical tubercle almost at 

 the middle of the side. 



Forms similar to this species occur in the Cambridge Greensand 

 and in the Red Chalk, and there exist (at Blackdown) transitions to 

 S. aeqnatorialis, Kossmat sp., on the one hand, and to the bituber- 

 culate species, referred to below, on the other. 



Locality. South side of Manuan Creek Valley. Coll. W. J. 

 Wybergh. 



10. SUBSCHLOENBACHIA BISPINOSA, UOV. 



(PI. XXIV, fig. 9.) 



This species is based on a somewhat fragmentary specimen 

 (No. 4993) that is weathei'ed on one side, so as to expose, in a natural 

 section, the distant septa of the inner whorls and the more approxi- 

 mate septa of the last quarter of a whorl, which shows the beginning 

 of the body-chamber. The dimensions are as follows : 



V 



Diameter .... 148 mm. 



Height of the last whorl . 32 per cent, of the diameter. 



Thickness ,, . 30 ,, 



Umbilicus .... 44 



The peculiar whorl-section (PI. XXIV, fig. 9), with its depressed outer 

 tubercle, shows the distinctive features of this form. The inner whorls 

 agree in ornamentation with those of the Bellegarde variety of 8. pre- 

 rostrata (B.M., No. C10547, less depressed than fig. 10, PI. XXIV), 

 and show spiral striation ; the outer whorl, with only a peripheral and 

 an umbilical tubercle (on the ribs that reach to the umbilicus) is 



