EURYPTERUS PUNCTATUS. 



155 



specimen, of which we give a woodcut above (see Fig. 49), is undoubtedly the median 

 appendage of the thoracic plate. 1 The upper portion is broadly sagittate or spear-shaped ; 

 the lower portion is quite straight and linear and is divided down the centre into two 

 equal parts for If inch, or nearly its entire length ; reminding one of the corresponding 

 appendage in the thoracic plate of E. lanceolatus, which is also bifid (see PL XXVIII, 

 fig. 2 a). The surface is destitute of ornamentation. 



Although I cannot accept the detached lip-plate (see pi. xi, fig. 4, 'Mem. Geol. Surv.,' 

 Mon. I), referred by Mr. Salter to this species, as really belonging to it, I am fortunately 

 in possession of a very fine example, also from Leintwardine, which was left with me by 

 Mr. Salter for examination some years ago, and from the fact of its close agreement in 

 form with the lip-plate of E. scorpioides just described (see PI. XXX, fig. 9), I feel 

 little hesitation in ascribing it to E. punctatus. 



Fig. 50. — Lip-plate of Eurypterus punctatus, Salter, sp., from 

 the Lower Ludlow, Leintwardine, Shropshire. Reduced 

 one-third. 



Form and dimensions of detached lip-plate (see Woodcut, Fig. 50), referred to 

 E. punctatus : — 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 terminating posteriorly in a rounded margin only 1^ inch in breadth. 



1 This part is described by Mr. Salter as the "epistoma" or the "conjoined epistoma and labrum " in 

 this and in all other species in his Monograph. 



