194 ME. It. B. NEWTON ON NON-MAEINE MOLLTJSCAN [June 1914, 



Crocodilian remains, and Ampullar ia ; and also in Bed 24 in a 

 greenish- grey clay or marl. 



Localities.— Kachuku (Beds 16, 19, & 24); Nira (Bed 24); 

 South Nira (Bed 24). 



Terrestrial Forms. 

 Family Pomattid^:. 

 Tropidophora nyasana (E. A. Smith). (PI. XXX, fig. 14.) 



Pomatias nyasanus E. A. Smith, Proc. Zool. Soc. London, 1899, p. 591 & pi. xxxv, 



fig. 5. 

 Ligatella nyasana W. Kobelt. Abhandl. Senckenberg. Naturf. Gesellsch. vol. xxxii 



(1909) p. 78. 

 Tropidophora nyasana R. B. Newton, Q.J. G. S. vol.lxvi (1910) p. 242 &pl. xviii, 



figs. 8-9. 



Remarks. — The specimen here referred to differs only from the 

 type in possessing fewer spiral costse, a variation which may be 

 found to exist when one is dealing with several specimens. Such is 

 really the case in connexion with some Quaternary forms of the 

 species from Nyasaland, which show well- separated and equi- 

 distantly arranged costse. The species itself is not only related to 

 Cyclostoma insular e of Pfeiffer from Natal, as pointed out by 

 Mr. E. A. Smith ; but there appear to be also some close affinities 

 with C. letoumeuxi Bourguignat and E. von Martens's variety of 

 the same, stuhlmanni, as well as with C. delmaresi Ancey, all of 

 which have been well figured by E. von Martens in his ' Beschalte 

 Weichthiere — Deutsch-Ost-Afrika ' [Mobius] 1898, vol. iv, pi. ii, 

 figs. 1, 2, & 5, pp. 4-6. Dr. Kobelt has recognized this species 

 under the genus Ligatella of E. von Martens, the type of which is 

 Miiller's Cyclostoma ligatum, a smooth shell. Those shells there- 

 fore, like that now under discussion, possess a prominently spiral 

 ornamentation (not present, however, on the two earliest whorls, 

 which are smooth as in recent examples of the species), and should 

 more accurately be regarded as belonging to Troschel's Tropidophora 

 of 1847, the type of which is the Cyclostoma cuvierianum Petit. 1 



Distribution. — The species has been recorded from late post- 

 Pliocene deposits near Lake Nyasa, being also found living on the 

 Nyasa plateau at Zomba. Only related forms [previously men- 

 tioned] are known as existing in the Victoria Nyanza region. 



Occurrence. — From Bed 8, associated with Limicolaria sp. 

 and Cerastus sp. 



L o c a 1 i t y. — Kikongo. 



Family Achatinid.e. 



Achatina sp. indet. (PI. XXX, fig. 12.) 



Remarks. — This genus is represented in the collection by a 

 summit fragment only, which has a height and diameter of 14 and 

 10 millimetres respectively. It is of short conical form, and 

 composed of five rather plano-convex whorls, including a smooth, 



1 Zeitschr. Malakozool. [Menke & Pfeiffer] 1847, p. 44. 



