152 BRITISH FOSSIL CRUSTACEA. 



Species 9.— EURYPTERUS SCORPIOIDES :— H. Woodward. PI. XXIX, fig. 1 ; 



PI. XXX, Fig. 9. 



'O' 



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



p. 292, pi. ix, fig. ; pi. x. fig. 2. 



Among the rich collection of fossil Crustacea from Logan Water exhibited by Mr. 

 Robert Slimon at the Meeting of the British Association at Dundee, in September, 1867, 

 were several new forms belonging to the order Merostomata, which have since been 

 acquired for the British Museum. 



One of these new forms is represented on PI. XXIX, fig. 1, by an almost entire indi- 

 vidual, measuring 1 1 inches in length and 5 inches in breadth, having one entire swimming- 

 foot and three pairs of palpi in situ, and presenting a part of the dorsal aspect of the body 

 to view. 



The counterpart of the anterior part of the same individual is preserved in the Museum 

 of Practical Geology, Jermyn Street (see PL XXX, fig. 9), exhibiting the ventral aspect 

 with the post-oral plate or metastoma ; the bases of the swimming-feet and three pairs of 

 perfect spinose palpi. 



Carapace semicircular in front, twice as broad as it is long. Eyes not distinctly 

 preserved, nor ocelli. 



Organs of the mouth consisting of five pairs of appendages ; the first and most 

 anterior pair not preserved (probably simple palpi, as in Slimonia, Slglonurus, and other 

 species of Eurypterus). Second, third, and fourth pairs 7 -jointed, very robust; fifth, 

 sixth, and seventh joints each armed with a pair of strong recurved spines, the palpi and 

 spines in both specimens directed forwards ; fourth joint armed with several short incurved 

 spines ; second and third joints without spines ; first joint serving as a maxilla, and armed 

 with serrated teeth. Length of palpi 3| inches, breadth at fourth joint \ inch. Spines 

 varying from f to 1 \ inch in length, and 2 lines in breadth. 



Swimming-feet or maxillipedes 7-jointed, Q>\ inches in length. Basal joint somewhat 

 triangular in form, 14 lines long, 10 lines in breadth at posterior border; maxillary border 

 concealed beneath the metastoma ; breadth of articulation between the ectognath and 

 second joint 8 lines, length of second joint 8 lines, of third joint 8 lines, of fourth joint 



10 lines, of the fifth joint 1^ inch, and breadth 10 lines; sixth joint \\ inch long by 



11 lines broad (a small triangular plate is inserted here as in Slimonia and in Pterggotus) ; 

 seventh joint If inch in length and 9 lines in breadth, with a minute nail 2 lines in length 

 and H line in breadth, inserted at its distal extremity. 



Lip-plate or metastoma shield-shaped, having its broadest border directed forward, 



