﻿EURYPTERUS PUNCTATUS. 159 



" A narrow (articular ?) furrow runs along the middle portion of the anterior edge, 

 followed by a convex ridge, which is bounded by a row of prominent minute tubercles, 

 extending a good way out, and nearly to the lateral margins. Behind this the anterior 

 third of the segment is occupied by the sculpture, which is much, more prominent and 

 tubercular, and less scale-like than in the large Scotch species." 



Mr. Salter adds — " 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 

 P. avglicus 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 ; and the mandibles, the palpi of which were strongly fringed with long curved 

 processes. As all these present distinctive peculiarities from other species, and as the 

 tuberculation on the various specimens found in this bed agrees in character, it is fair 

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



As regards the form of the body-segments, Mr. Salter's evidence is most valuable in 

 confirmation of the identity of these remains ; for in the Survey Monograph he figures 

 (p. 101) five of the anterior body-rings from Leintwardine, which agree closely in form 

 with the specimen from Lanarkshire. He also observes (p. 99) that " the hinder segments 

 were decidedly longer in proportion to their width than in Pterygotus Anglicus, or PL 

 gigas." Indeed, one of the segments which he has figured (Mon., pi. x, fig. 5) most 

 clearly shows this to be the case. 



From the evidence derived from the nearly related Lanarkshire specimens (already 

 described), I venture to refer this form to Mtrgpterus ; it will probably come near Hall's 

 Eurypterus pachych eirus. 1 



But the specimens from the Lower Ludlow Rock give evidence of a species twice the 

 size of that occurring in Lanarkshire ; there are also sufficient points of distinction in the 

 form of the metastoma, the joints of the swimming-feet, the armature of the palpi, &c, 

 to distinguish them specifically. I therefore propose to retain the name of punctatus for 

 the Ludlow remains, as indicated, adding thereto the great lip-plate (see Woodcut, Fig. 50) 

 already referred to. 



I will merely add that I have received from Mr. Charles Ketley a series of five narrow 

 abdominal segments of a crustacean from the Wenlock Limestone, Dudley, the markings 

 upon which lead me to refer it to Eurypterus punctatus. Other portions, bearing similar 

 punctate ornamentation, easily distinguished from the ordinary squamate markings so 

 characteristic of Pterygotus, have been obtained, and obligingly submitted to me for 

 examination, from both the Wenlock Shale and Limestone, by Mr. John Gray, Mr. E. 

 Hollier, Mr. Allport, and Mr. Johnson. 



Formations and Locality : — Upper Ludlow Rock, Whitcliffe, Ludlow, Kendal, West- 

 moreland ; Lower Ludlow Rock, Church Hill, Leintwardine ; Wenlock Limestone and 

 Shale, Dudley. 



1 And probably also near his subgenus Boliehopterus. 



