292 PROCEEDK^^GS OF THE GEOLOGICAL SOCIETY. [March 25, 



Form and dimensions of detached lip-plate (PL IX. fig. 2) referred 

 to E. jpunctatus : — form, that of an armorial shield with its anterior 

 corners truncated ; greatest anterior breadth 4 inches, length 5 

 inches ; sides curving inwards, and again expanding, then termi- 

 nating posteriorly in a rounded margin only 1^ inch in breadth. 



2. Efrtpteeus scorpioides, sp. nov. PL IX. fig. 1, & PL X. fig. 2. 



Carapace semicircular in front, twice as broad as it is long. Eyes 

 not preserved, nor ocelli. 



Organs of the mouth furnished with five (?) pairs of appendages, 

 the first and most anterior pair imperfectly preserved (probably 

 simple palpi as in SUmonia, Stylonurus, and certain species oiEury- 

 pterus) . Second, third, and fourth pairs 7-jointed, very robust ; fifth, 

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

 the palpi and spines (in both specimens known) directed forwards ; 

 fourth joint armed with several short incurved spines ; second and 

 third joints without spines ; first joint serving as a maxiUu, and 

 armed with serrated teeth. Length of palpi ^\ inches, breadth at 

 fourth joint \ inch. Spines varying from | to 1\ inch in length, 

 and 2 lines in breadth. 



Swimming -feet or maxiUipedes 7-jointed, 6^ 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 1^ inch long by 11 lines broad (a small tri- 

 angular plate is inserted here as in Slimonia and Eurypterus, and 

 probably also in Pteri/gotus) ; seventh joint 1| inch in length and 9 

 lines in breadth, with a minute nail 2 lines in length and 1^ line in 

 breadth, inserted at its distal extremity. 



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

 directed forward, 10 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. — Pirst | an 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, orna- 

 mented with two subcentral wart-Hke spots ; surface punctated. 



Third segment 10 lines long in the centre, by 5J inches in 

 breadth, ornamented in the same manner as the second segment. 



Fourth segment 10 lines in length and 5^ inches in breadth, 

 border cuiwed, marked subcentrally by two drop- shaped prominences 

 4^ lines long. 



Fifth segment 9 lines in length and 4| inches in breadth, orna- 

 mented as the fourth segment. 



