BRITISH FOSSILS. 



PLATES X., XI., AND PART OP XIII. 



PTEEYGOTUS PUNCTATUS. 



P. magnus, (5-6 pedalis?) capite (?), segmentis omnibus squamulis 



remotis prominulis ornatis, in articulis posticis per totum annulum sparsis ; 

 chelis antennarum elongatis ; palpis longi-fimbriatis. Pedibus natatoriis 

 articulo terminali elongate, penultimo expanso. 



Of this very large and distinct species various fragments have 

 from time to time come to light, and have been communicated by 

 our friends Messrs. Lightbody, Cocking, and Marston, of Ludlow, 

 and especially from the cabinet of H. Pardoe, Esq. 



They are from the quarry at Leintwardine, Shropshire, in the 

 Lower Ludlow Rock, where many fine starfish and other rarities 

 have been newly discovered. (Siluria, 2nd edition, p. 140.) 



There is evidence of at least three, if not more, of the thoracic 

 rings. The hinder segments were decidedly longer in proportion to 

 their width than in the P. anglicus or P. gigas. We have also the 

 swimming paddles, which, without the great coxal joints, were 

 seven inches long, expanded in the penultimate joint and attenuated 

 at their tips ; of the mandibles, the palpi of which are strongly 

 fringed with long curved processes, and of antennae, witli slender 

 pincers at their terminations, and armed with numerous small 

 conical teeth. As all these parts present distinctive peculiarities 

 from other species, and as the tuberculatiou on the various speci- 

 mens found in this bed agrees in character, it is fair to combine 

 them as a single species, and figure them all upon one plate. 



Of the carapace or eyes we have yet no trace. But the epistoma 

 (fig. 1) presents us with a singularly neat character for the species. 

 The upper portion of this organ is broadly sagittate or spear-shaped as 

 in other species, and offers a wider basal angle than that of P. angli- 

 cus, but the outer portion, which is quite straight and linear, (instead 

 of being clavate,) is bilobed at the tip ; and from the deep terminal 

 notch a raised central line is continued nearly all the way up the 



