262 



PROCEEDINGS OE THE GEOLOGICAL SOCIETY. [Mar. 22' 



from any species previously examuied by me, and of which I beg to 

 subjoin a short notice. 



The most perfect specimen, from which the restored outline (fig. 1) 

 is taken, measures 2| inches in length, and 10 lines in its widest 

 thoracic segment. All the somites are united ; and one of the swim- 

 ming-feet, although injured, is still in place. The head, which is 

 semicircular in outline, measures 4 lines in length by 9 lines in 

 breadth ; the eyes are subcen- ^ 



tral, and the ocelli nearly cen- 

 tral, as in the other species of 

 Earypterus. The first six seg- 

 ments (thoracic) succeeding 

 the head measure together 9 

 lines in length ; commencing 

 with a breadth of 9 lines, they 

 increase at the third segment 

 to 10 lines, and diminish at 

 the sixth segment to 7 lines in 

 breadth. The segments in- 

 crease in length and diminish 

 in breadth very evenly from 

 the third segment backwards. 

 The borders of all the anterior 

 segments are curved, and the 

 posterior angles slightly pro- 

 duced and acutely pointed. 



The six posterior (abdo- 

 minal) segments diminish in 

 breadth backwards from 6 

 lines to 2 lines, and increase, 

 in the same direction, in length, 

 from 1| line to 2^ or nearly 

 3 lines, the body being ter- 

 minated by a slender ensiform 

 telson, or tail-spine, 7 lines 

 in length. No sculpture is 



apparent on the segments or head; but the integument com- 

 posing the former indicates its tenuity by abundance of plicae 

 and wrinkles. The thoracic plate (fig. 3) is very characteristic, 

 difPering in the form of its median appendage from that of any 

 previously described species. It is 9 lines broad, and 2| in depth ; 

 the median appendage is spindle-shaped in outline, and is 3J 

 lines in length and Ig line broad. The swimming-foot is 21 

 lines in width, and | of an inch in length, exclusive of the basal 

 joint. The species agrees closely, in the form of its swimming -feet, 

 with the American and Russian Eurypteri, having the same inter- 

 calated plate between the ultimate and penultimate joints, and 

 also the minute terminal palette at the end of the seventh seg- 

 ment. 



Numerous detached endognathary palpi occur associated with this 



Pig. 1. Eurypterus Brodiei, H. Woodw. 

 (outline restored, natural size). Passage- 

 teds from the Uppermost Silurian to the 

 Old Eed Sandstone, Perton, near Stoke 

 Edith, Herefordshire. 



Fig. 2. Palpus (enlarged). 



Fig. 3. Thoracic plate (enlarged). 



