The Invertebrate Fauna of the Uitenhage Series. 197 



A shell from the Lower Hauterivian of North Germany described 

 by von Koenen * under the name Astieria aff. psilostoma also shows 

 great similarity to H. wilmana, but may be readily distinguished by 

 the wider umbilicus, the strongly developed constrictions, and the 

 more inflated and less discoidal form of the whorls. 



Pavlow thought that small specimens from the Neocomian of 

 Spain, figured by Nickles t as Holcostephanus hispanicus, might 

 possibly belong to this form ; but though a thorough comparison 

 with these figures is difficult, and the character of the ribbing 

 appears to be very similar, it seems to me most probable that the 

 much greater inflation of the Spanish shell would be found sufficient 

 to separate it. If the specimen figured by Nickles in fig. 11 

 represents the same form as that depicted in fig. 3, then it is clear 

 that H. wilmana is a much more discoidal shell. The small 

 specimen represented by Nickles in fig. 10 is only drawn in side 

 view, but it appears to possess a prominence of the umbilical rim 

 and a depth of the umbilical cavity which may be taken to indicate 

 the somewhat strongly inflated character of the shell. Pavlow draws 

 attention to the existence of two specimens which he identifies with 

 the South African form above described ; the one is from Aigles 

 (Basses- Alpes), preserved in the Pictet collection in the museum at 

 Geneva, and the other, from the Shasta group of California, is in the 

 geological collection of the University of Moscow. 



Holcostephanus tonsbergensis (Weerth),| from the Neocomian of 

 the Teutoburger Wald, may possibly also be related, so far as can be 

 judged from a comparison with Weerth's figure 4. 



HOLCOSTEPHANUS BAINI (Sharpe). 

 1856. Ammonites bainii D. Sharpe, Trans. Geol. Soc. Lond., ser. 2, 



vol. vii., p. 197, pi. xxiii., fig. 2. 

 1882. Olcostephanus baini M. Neumayr, in E. Holub and M. 



Neumayr, Denkschr. d. k. Akad. Wiss., Math-Nat. 01., 



Band xliv., p. 272. 



Although no specimen undoubtedly referable to this form is 

 included in the collection under examination, a few remarks under 

 this heading may be useful as a preface to the account of an 

 individual, to be described below, which I believe to be very closely 

 related to H. baini. 



* von Koenen (2), p. 151, Taf. liv., fig. 2. 

 . f Nickles (1), pi. ix., figs. 3 and 10. 

 J Weerth (1), p. 16, Taf. iv., fig. 4. 

 14 



