82 Transactions of the Boyal Society of South Africa. 
regularity on the umbonal region, with the exception of the surface 
of the incurved part of the umbo, which is much worn and without 
sculpture, where they are finest and most numerous, the coarsest 
occurring in the antero-ventral direction where they also become 
broader and more irregularly disposed ; the separating grooves are 
also widest in the same area. 
The coarser costae take a more or less curved direction before 
reaching the anterior margin of the valves. Mention should also be 
made of the presence of a series of similarly broad costse, which are 
almost obsolete and quite subsidiary to the V-shaped ribs, these 
being of concentric contour and apparently parallel with the ventral 
margin. 
Dimensions (specimen with united valves). — 
Height 41 mm. 
Diameter 29 
This specimen appears to show no particular relationship to the 
few Cretaceous Goniomyce already known in literature. It is of 
much greater height than the European Cenomanian form originally 
described by Orbigny as Pholadomya mailleana besides having the 
costal apices vertically arranged from the umbones downwards 
instead of extending more or less obliquely to the postero-ventral 
extremity. 
A closer afiinity may perhaps be traced with Lysianassa designata 
of Goldfuss (Petrefacta Germanise, 1840, vol. 2, pi. 154, fig. 13, p. 264) 
from the Senonian of Bohemia, which, according to the original 
figure, has a fairly long and oblique anterior margin, a deep umbono- 
ventral measurement, and a surface sculpture (although only partially 
shown on account of the specimen being a probably eroded cast), 
indicating the presence of a series of vertically disposed angulated 
ribs. The imperfection posteriorly of the specimen from Zululand 
prevents any estimate of its original length being made, so that 
further comparison with a form like designata, which has a widely 
elongate posterior region, is of little or no value. Apparently no 
Cretaceous GoniomycE have been recorded from India, and further 
they appear to be exceedingly rare in African strata, although 
M. Alphonse Peron has recorded G. mailleana from the Cenomanian 
of Tunis (Desc. Moll. Foss. Terr. Cretaces Tunisie, Exi^lor. Scientif. 
Tunisie, 1890-1891, pt. 2, p. 327), and Mr. Woods has recently 
figured and described {Ann. South African Museum, 1906, vol, 4, 
part 7, pi. 37, fig. 9, p. 310) Goniomya sp. from the Cretaceous of 
Pondoland which is of small size and in no way comparable to the 
fragment now described. 
Locality. — Tributaries of the Manuan Creek. 
