On new Mollasca from South Africa. 163 



Professor Marsh figures the base of the skull of \_Theco- 

 dontosaurus] inlatyodon^ of which no example is known in this 

 country in any museum. 



Figures are also given of the bones of the left fore leg of 

 the same species, in which are shown the scapula and cora- 

 coid, the humerus, radius, ulna, two carpal bones, and five 

 metacarpals. There are three digits bearing claws with two, 

 three, and four phalanges ; the fourth digit has three minute 

 phalanges, and in the fifth a hypothetical phalange is indi- 

 cated. The claws decrease in size from the first to the third. 

 No such specimen exists in this country. The forms of the 

 bones are similar to those which I have attributed to Palceo- 

 saurus lAaiyodon, with which they correspond in proportion, 

 though, as the figure is one-fourth natural size, the animal 

 appears to be sligiitly smaller than that of which I have given 

 particulars. It is unexpected to find so Crocodilian a type of 

 limb with the metatarsals extended as though they were 

 carried vertically. 



As the Bristol Museum specimens all came from a working 

 long since closed, it would be interesting to learn the source 

 from which these important new materials have been obtained. 



XVIII. — Descriptions of Four new Species of Terrestrial 

 Alollusca from South Africa. By James Cosmo Melvill, 

 M.A., F.L.S., and John Henry Ponsonby', F.Z.S. 



[Plate XII.] 



Zingis delicata, sp. n. (PI. XII. figs, 1, 1 a.) 



Z. testa imperforata, depresso-orbiculari, teniii, nitidu, corneo- 

 succineata ; aut'ractibus sex, apud suturas iinpressis, fere laevibus, 

 sub lente iufra suturas et circa regionein umbilicarem transversim 

 teuuissime striatis, striis mox evanidis, longitudinaliter irregu- 

 lariter oblique liratis, ultimo anfractu apud medium laevissimo; 

 apertura ovata ; peristomate teaui, axi columellari albescente, 

 paullum incrassato. 



Long. 9, lat. 16 mill. 



Hah. Knysna {Cox). 



An extremely beautiful, imperforate, transparent species, of 

 a dark brown warm amtaer colour; thin, fragile, depressed 

 orbicular in form, six-whorled, with much flattened spire and 

 apex; apparently quite smooth and shining, but with the aid 

 of a lens the surface below the suture is seen to be very finely 



