EURYPTERUS PUNCTATUS. 153 



1 lines in breadth and the same in greatest length, anterior angles truncated, sides 

 gradually converging towards the posterior border, which terminates in an obtuse angle. 



Thoracic plate imperfect, but having a median appendage as in other species. Surface 

 punctate. 



Body-segments. — First \ inch long by 4 inches in breadth, curving upwards at the 

 centre-line downwards on each side and upwards and inwards on its lateral borders. 



Second segment 7 lines long in the centre by 4f inches in breadth ; margin curved in 

 a corresponding manner to the first segment, ornamented with two subcentral wart-like 

 spots ; surface punctated. 



Third segment 10 lines long in the centre by 5^ inches in breadth ; ornamented in the 

 same manner as the second segment. 



Fourth segment 10 lines in length and 5| inches in breadth ; border curved, marked 

 subcentrally by two drop-shaped prominences 4^ lines long. 



Fifth segment 9 lines in length and 4^ inches in breadth ; ornamented as the fourth 

 segment. 



Sixth segment 8 lines in length by 3f in breadth ; surface punctated. 



Seventh segment 11 lines in length by 2§ in breadth ; surface punctated. 



Eighth segment 1 inch in length and If inch in breadth; surface punctated. 



Ninth segment 10 lines in length and 1^ inch in breadth. 



Tenth segment 10 lines in length and 1^ inch in breadth. 



Eleventh segment 11 lines in length and \\ inch in breadth. 



Twelfth segment 1 inch in length and 1 inch in breadth. 



Telson wanting, probably ensiform, as in other species of Earypterus. 



The punctate ornamentation is well seen on the anterior body-segments, and is at once 

 readily to be distinguished from the scale-like markings observable on the body of 

 Pteryyotus and Slimonia. 



Formation and Locality. — Uppermost Silurian, Lesmahagow, Lanarkshire. 



Species 10.— EURYPTERUS PUNCTATUS -.—Salter, sp. PI. XXIX, fig. 2. 



Pterygotus punctatus, Salter. Mem. Geol. Surv., Mon. I, 1859, p. 99, pi. x ; pi. xi, 



figs. 5—9, and 12—15 ; pi. xiii, figs. 5, 6, 9, 10, 11, 14. 



Eurypterus punctatus, H. Woodward. Quart. Journ. Geol. Soc, 1868, vol. xxiv, 



p. 290. 



This species, established by Mr. Salter in 1859, upon a series of detached appendages 

 and fragmentary remains from the Upper and Lower Ludlow Rocks of Leintwardine, 

 Shropshire, is closely related to, but distinct from, Eurypterus scorpioides, just described, 

 from Logan Water. 



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