The Invertebrate Fauna of the Uitenhage Scries. 31 



of some of the more important fossils, together with their supposed 

 extra-African allies and analogues, which, with one exception, were 

 thought to be Jurassic. An examination of this list shows, however, 

 that a different construction must now be put upon the comparisons, 

 as may be demonstrated by the mention of a few examples. In 

 addition to Holcostephanus atlierstoni and H. baini, which were 

 erroneously thought to be allied to well-known Oolitic forms, there 

 is Tate's Ammonites subanceps, a single specimen, regarding which 

 that author wrote : " It is doubtful whether this be not a mere variety 

 of A. anceps Eeinecke, of the Middle Oolites." As already men- 

 tioned, Neumayr thought that it might represent a stage in the 

 individual growth of Crioceras spinosissimum, which he supposed 

 to have had the whorls in contact at such an immature period. 

 This may be a correct view, but it seems equally probable that 

 we are dealing with an immature example of some species of 

 Hoplites (sensu lato). Tate's specimen, of which his published 

 figures convey a very imperfect and even misleading impression, 

 shows great similarity to certain forms which have been ascribed 

 by Sayn to Hoplites arnoldi (Pict. and Camp.), and by Toucas 

 to H. botellce Kilian. These were thought by Pavlow to have 

 been wrongly identified, and are united by him under the name 

 Hoplites lieteroptyclius, which has more recently been included by 

 Uhlig in his narrower generic group Solgeria. A somewhat similar 

 form has been described and figured by Bogoslowsky under the 

 name Hoplites aff. arnoldi Pict., and this is said to occur with 

 Belemnites lateralis Phill. above the " Ejasan-Horizont " in Eussia 

 (Mostja Eiver). : ' : Hoplites subanccps is more closely and less 

 coarsely ornamented than this, but there are points of agreement 

 in the type of sculpture. Further observations on "Ammonites" 

 subanceps are given in the remarks which follow the description 

 of a specimen ascribed to Acanthodiscus sp., in the following pages. 



Ostrea jonesiana Tate was compared by Tate with 0. costata Sow. 

 from the Oolites ; but it is in reality a true Exogyra quite compar- 

 able with shells of the type of E. suliplicata Eoem.,t from the 

 Hilsconglomerat of North Germany. 



Pectcn projectus was compared with P. lens Sow., but such a com- 

 parison must have little value when we remember that species of 

 Pecten with similar broad characteristics recur at various horizons 

 and are not confined to the Jurassic rocks. Pecten projectus, in 



* Bogoslowsky (1), pp. 112, 138; Taf. vi., fig. 7. 



f F. A. Roemer (1), Nachtrag, p. 25, pi. xviii., fig. 17; F. A. Eoemer (2), p. 47 

 (1840). 



