308 Annals of the South African Museum. 



type came from the Blackdown Greensand. In the former, how- 

 ever, the concentric ribs and furrows are broader and less numerous 

 than in the examples from Blackdown. The Pondoland specimens 

 agree closely with those from the Trichinopoh Group, which were 

 referred by Forbes and by Stoliczka" to P. Hillana. 



The specimens from the Libyan desert, figured as P. Hillana by 

 Quaas,t have the ribbing coarser than in the examples from Black- 

 down. P. hiseriata (Conrad),]: from the Chalk of Syria, possesses 

 still coarser concentric ornamentation. 



The Pondoland form does not appear to differ from P. Hillana var. 

 umkxoelanensis, Etheridge,§ but I have had no opportunity of com- 

 paring specimens. The largest example from Pondoland which I 

 have seen is in the Hamburg Museum, and agrees in size and form 

 with Etheridge's figure, but possesses more numerous ribs. 



P. Hillana is abundant in the Blackdown Greensand, and varies 

 to some extent in its ornamentation, but I have seen no specimen 

 with the ribs so coarse as in the examples from the deposits men- 

 tioned above, and usually they are considerably finer. 



Family SOLENID^. 

 Genus SOLECUETUS, BlainviUe. 



SOLECUETUS? (AZOR?), Sp. 



Plate XXXVII., fig. 7. 

 There are two specimens which resemble Solen Guerangeri, 

 d'Orbigny,|| but are less elongated. In this respect, however, they 

 agree with the example of that species from the Senonian of Chlomek 

 (Bohemia) figured by Fritsch.' Unfortunately the Pondoland speci- 

 mens are very imperfectly preserved, so that an exact determination 

 is at present impossible. Both specimens are left valves ; one shows 

 the exterior, but is much decorticated, so that the nature of the orna- 

 mentation cannot be seen ; the other example shows the interior, 

 but the characters of the hinge, the muscular impressions, and the 



* Cret. Fauna S. India (1870), p. 219, pi. xii., figs. 8-10, pi. xiii., figs. 1-3. 



t Obei-st. Kreidebild. i. d. libyschen Wiiste (Palteontographica, vol. xxx., 2, 1902), 

 p. 218, pi. xxiv., figs. 18, 19. 



+ n. B.' Newton, Geol. Mag. (1898), p. 400, pi. xv., fig. 11. 



§ Second Report Geol. Survey Natal and Zululand (1904), p. 79, pi. i., fig. 16. 



II Pal. Franv Terr. Cret., vol. ill. (1845), p. .321, pi. cceli., figs. 1-2. Gueranger, 

 Album Paleont. de la Sarthe (18(57), p. 12, pi. xv., fig. 4. 



% Stud, im Geb. d. bohm. Kreidef., vi. Chlomek. Schicht. (1897), p. 58, fig. 68. 



