Mr. Salter on Palaozoic Fossils from South Africa. 215 



lobed dorsal margin. Keel probably none. Aperture semilunar, indented on each 

 side above by the sulci, and more than twice as broad as deep. Diameter of the 

 shell f of an inch. 



This is closely allied to such forms as B. (Euph.) trilobatus, Sow., and jB. bisul- 

 catus, Rom., from both of which its broad, flattened, and almost double dorsal lobe 

 distinguishes it. There is no appearance of a band ; and we think that this 

 group of smooth and but slightly expanded Bellerophons may be distinguished by 

 the subgeneric name formerly applied by Prof. M'Coy (see Pal. Foss. Cambridge 

 Mus. p. 308). 



Locality. — Warm Bokkeveld. 



Theca subaqualis, Salter. Woodcut, figs. 3, 4. 



T. conica, compressa, nee trigona ; facie dorsali rotundat^, ventrali lente convexa ; test^ 

 crassiuscula ? sublaevi, striis arcuatis obscuris. 



Length f inch, width 3 lines. Shell rather thick, quickly tapering, smooth or 

 crossed only by lines of growth ; ventral side gently convex, the dorsal more convex 

 and subangular, but with the angles quite rounded off. 



It is difficult to distinguish accurately the species of this genus. The present 

 appears distinct from any published. It might have been referred to the T. lan- 

 ceolata, Sowerby and Morris, from New South Wales*, but that species has a more 

 trigonal internal cast, as particularly mentioned by Sowerby, and distinct regular 

 transverse strise. Both species appear to have had rather a stouter shell than 

 usual in the genus. 



Locality. — Occurs as a ferruginous cast, together with Bellerophon quadriloba- 

 tus and Tentaculites crotalinus, in a nodule of dark-grey rock from the Warm 

 Bokkeveld. 



Description of PaleBOZoic Crustacea and Radiatafrom South Africa. 

 By J. W. Salter, Esq., F.G.S. 



Homalonotus Herschelii, Murchison, Silurian System, pi. 7 bis, fig. 2 ; Burmeister, 

 Organ. Trilob. (ed. Ray Soc.) p. 87. PI. XXIV. figs. 1-7. 



H. longus, pedalis, spinosus ; capita triangulate, fronte in apiculura curvum producto ; 

 thorace armato ; cauda convexissima, trigona, acuta, annulis sexdecim, nonnullis spinosis. 



Of this fossil, which we previously knew only from fragments, Mr. Bain has 

 collected a fine series, showing the upper and under side of the head, with its 



* Strzelecki's ' New South Wales,' 1845, p. 289. 

 VOL. VII. SECOND SERIES. 2 G 



