BRITISH FOSSILS. 



PLATE XII. FIGS. 22-46. 



PTERYGOTUS BANKSII. 



P. parvulus, 4-5 uncialis, capite convexo, semiovali, vel parabolico, 

 ad frontem subangulato, oculis brevibus gibbis, ad dimidium capitis : 

 annulis trunci omnibus transversis, cauda expansa truncata biloba. 



SYNONYM. Himantopterus Banksii, SALTER, Quart. Journ. Geol. Soc. 

 vol. vii. p. 32, also p. 99. and pi. 2. fig. 5. [fig. 6, is the caudal joint of an 

 Eurypterus]. Siluria, 2nd ed. p. 266. foss. 66. fig. 1. 



Named in honour of Richard Banks, Esq., of Kington, Hereford- 

 shire, who has made rich collections of the Pterygoti of that locality, 

 and has generously relinquished the publication of his materials in 

 our favour. He has also presented to the Museum all his accurately 

 coloured drawings and notes. 



" This small neat species, of which we have many specimens in 

 the Museum of Practical Geology, occurs with Pterygotus (P. gigas, 

 Plate VIII.), and spines both of Crustacea and fish, in the yellow 

 tilestone (Downton Sandstone) beds of Kington, Herefordshire. It 

 is there associated with the Platyschisma helicites and Lingula 

 cornea, Sil. Syst. These are the two species of shells which accom- 

 pany the fossils of Lesmahago above described, a good argument, 

 therefore, even without other evidence, for regarding these Lesma- 

 hago beds as the uppermost portions of the Ludlow rock." Quart. 

 Oeol. Journ. I. c. 



Description. The full size must have been from four to five inches 

 long, but the specimens usually met with would probably not be 

 above three or four inches. One or two show the connexion of the 

 body rings with the head and appendages, fig. 42, or with the tail 

 joint (fig. 23). None are quite complete, and though we have nearly 

 all the parts, they are usually disjointed. 



The carapace (fig. 22) is a broad semioval, its length as six to 

 seven, except when lengthened or shortened by pressure (figs. 25, 26). 

 It is regularly convex, a little angulated in front, smooth, and bears 

 the small oval eyes rather more than half-way up the head. They 



