DESCRIPTIONS OF NEW CHITONS. 287 



Art. V. — Descriptions of some new Chitons. By Mr. G. B* 

 So WE KB Y, Jun. 



Sir, 



Having lately examined the principal collections of shells, for 

 the purpose of making a revised list of the species of the genus Chiton, 

 I have met with the following which I am unable to refer to described 

 species. As this genus is one of great interest, I am desirous of making 

 the new species known by their publication in the ' Magazine of Natural 

 History,' and I have, therefore, drawn up the accompanying descriptions, 

 with drawings of such of them as appear to me most worthy of illustra- 

 tion. * 



Editor of the Your's &c., 



Mag. Nat. Hist.' G. B. SOWERBY, Jun. 



Chiton hrevispinosus. (Supp. PI. xvi. fig. 1). 



Ch. testa nigra, depressa, ovali, antice sub-attenuata ; dorso rotundato, 

 laevi ; lateribus concentrice undulato-granulatis ; areis lateralibus vix dis- 

 tinctis ; margine spinis brevibus, nigris, numerosis instructo. Long. Ij^; 

 lat. 1^5 poll. 



Ins. Johanna, E. Africa. Mus. Cuming. 



Differing from Ch. spinosus, in the number and length of 

 the spines, as well as in the sculpture of the valves, this 

 species forms a pretty addition to the thorny-margined sec- 

 tion of Chitons. It is rather flat, oval, narrowed in front ; 

 the valves are rounded and smooth at the beaks, and granu- 

 lated at the sides, in undulating, concentric ridges ; an in- 

 distinct beaded rib met by strict at acute angles, separates 

 the lateral from the dorsal areas ; the numerous short black 

 spines studding the margin, are tipped with light yellow 

 points, which afford a pretty relief to the general black co- 

 lour of the shell. 



Chiton spiniger. (Supp. PI. xvi. fig. 2). 



Ch. testa depressa, ovato-elongata omnino granulata ; valvis reclinen- 

 tibus, tenninalibus rotundatis ; margine lato, spinis subarcuatis numerosis 

 instructo. Long. 2,^ ; lat. H, poll. 



Hab. ? Mus. Stainforth. 



Another spiniferous species, rather narrow in proportion 

 to its length ; depressed and finely granulated ; the valves 

 are rounded at the lateral extremities, with their apices lean- 



» The illustrations to this paper will be given in the next number of the 

 Supplementary Plates. — Ed. 



