138 BRITISH FOSSIL CRUSTACEA, 



Head, 5^ inches in length. 

 Six anterior (thoracic) body-segments, 4^ inches. 

 Six posterior (abdominal) do. 6 „ 

 Caudal spine (?)... 6 „ 



The caudal spine and appendages of this species at present remain unknown, but as 

 all the other species of Eurypterida possessed a more or less ensiform tail-spine, we may 

 pretty safely conclude that E. Scouleri was furnished with a similar organ. 



Although there is, at present, no absolute necessity to establish a distinct genus for 

 E. Scouleri, not being as yet fully acquainted with all the details of its structure, never- 

 theless I think it right to point out that this species presents many anomalies and con- 

 siderable divergence from the type-form of E. remipes (Fig. 40, p. 132). In the curious 

 form of the eyes, elevated above the carapace, upon a round base or peduncle, and in the 

 singular bifurcating median ridges or crests between the eyes, we are reminded of Stylo- 

 nurus Scoticus ; but the rounded, almost hemispherical, head-shield finds its analogue 

 alone in the carapace of the modern Limulus. In point of size, also, E. Scouleri 

 claims a place among the largest of the Merostomata. In geological position this species 

 is one of the latest, if not the very last, representative of the Eurypterida in the Palaeozoic 

 rocks. 



Formation. — Lower Carboniferous Freshwater Limestone. 

 Locality. — Burdie House, near Edinburgh. 



The associated fossils with E. Scouleri at Burdie House are — 

 Reptilia : — P holidoy aster piscif or mis, Huxley. 



Fishes : — Eury?wtus crenatus, Ag. 

 Uronemus lobatus, Ag. 

 Bhizodus Hibberti, Ag. 

 Meyalichthys Hibberti, Ag. 



Gyracanthus tuberculatus, Ag. 



„ formosus, Ag. 

 Palceoniscus Bobisoni, Hib. 



,, striolatus, Ag. 



Together with Sp/tenopteris ajfmis, Lindl., Stems, Leaves, and Fruits of Lcjridodendron , 

 Catamites, and many other plants. 



The beds are also exceedingly rich in Entomostraca. 



Original specimens in the collection of James Powrie, Esq., F.G.S., Reswallie, Forfar, 

 and of the Andersonian University Museum, Glasgow. 



A restoration of this singular Palaeozoic Crustacean, based upon the specimens 

 figured in Pis. XXVI and XXVII, is attempted on the opposite page. Only fragments 

 of the appendages are at present known. 



