Cretaceous Gastropoda, and Pelecy^joda from Zuhdand. 47 
Inoceramus expansus, W. H. Baily. 
Plate IX., figs. 1, 2. 
Inoceramus expansus, W. H. Baily, Quart. Journ. Geol. Soc, 1855, 
vol. xi., pi. 13, fig. 5, p. 462 ; C. L. Griesbach, Quart. Journ. 
Geol. Soc, 1871, vol. 27, p. 62 ; H. Woods, Annals S. African 
Museum, 1906, vol. iv., part 7, p. 299. 
Observations. — The original description of this species states that 
the shell is " ovate, oblique, rather depressed, sub-sequivalve, with 
concentrically prominent plications, hinge-margin elongated." 
Mr. Anderson's specimen is represented by a natural concavity in 
the matrix, which exhibits the internal impression of what was 
probably a right valve showing a marginal extension in both 
directions of 120 mm. ( = 4f inches), and a depth through of 
about 38 mm. As the margins are very incomplete more accu- 
rate dimensions are most uncertain. The sculpture markings 
consist of a series of distant, elevated, concentric plications with 
rounded summits, which are separated by wide, well-excavated 
furrows, bearing obscure concentric striations ; remains of the 
nacreous lining of the valve are still partially preserved. 
According to Captain E. J. Garden, who collected the fossils 
described by W. H. Baily, this shell is of abundant occurrence 
in the Umtamvuna Eiver district of South Africa, and sometimes 
attains a considerable size, as he had seen examples of from 2 to 
3 feet in length (Quart. Journ. Geol. Soc, 1855, vol. xi., p. 453). 
The British Museum has a specimen almost a foot from the umbo 
to the ventral region, but being fractured in that part, it is possible 
that, under more perfect conditions, it might have extended much 
further in that direction. Some of the convex natural casts of 
this species in the same museum have their surfaces studded 
with numerous rounded pittings from 1 to nearly 3 mm. in 
diameter, which must have resulted from the presence of corre- 
sponding prominences on the inner surface of the valves, and 
which were most probably of the nature of pearls on account of 
the nacreous character of the genus Inoceramus. Such a structure 
is well displayed on a figure published by Goldfuss (Petrefacta 
Germanise, 1836, vol. 2, pi. 112, fig. M, p. 116) of a specimen from 
the Senonian of Westphalia regarded as Inoceramus cripsi — a deter- 
mination which was subsequently altered to I. goldfussianus by 
Orbigny (Paleontologie Prancaise Terr. Cretaces Lamellibranchia, 
1845, pi. 411, p. 517) on account of the shell differing from one 
previously described by Mantell under the same name from British 
Cenomanian ( = grey chalk marl) rocks (Geology of Sussex, 1822, 
pi. 27, fig. 11, p. 133). 
