208 



THE CARBONIFEROUS SYSTEM. 



referred roe to a group of parasitic Amphipods (the Hyperina), 

 among which there are a few forms* with tail segments coalesced 

 and bearing appendages. These show a sufficient resemblance to 

 warrant our referring Diplostylus provisionally to the Amphipod order. 

 I am very much obliged to Mr Bate for this analogy (which would 

 certainly have escaped me in Milne-Edwards's work). Mr Bate's late 

 papers on the Amphipods (Ann. Nat. Hist., 1861) admirably illustrate 

 this peculiar group. 



" Eurypterus, a large species allied to E. Scoideri, Hibbert (Fig. 50). 



" A mere fragment of a large body-ring, which neveiiheless indi- 

 cates a species nearly as large as the great Scotch Eurypterus (E. 

 Scouleri, Hibbert). 



"The large ' teardrop -tubercles' along the hinder margin suffi- 

 ciently show the nature of the ornament. These, in all probability, 

 were replaced by spines on the carapace, as in the British Coal 

 measure species. 



" The carbonaceous film which remains in part on the surface, 

 cracked (by shrinking) into minute areolae, represents evidently a 

 corneous substance, from which the animal matter has been dissolved 

 away. The suggestion of Professor Huxley, that the large Euryp- 

 teridce had a thick crust like that of Limulus, with but little 

 calcareous matter, is most probably true. 



" Locality — Coal measures, Port Hood, Cape Breton. 



Fig. 50. — Fragment of Eurypterus. Fig. 51. — Tail of Eurypterus (?). 



"Eurypterus (?), tail of. (Fig. 51). 



"This small specimen, found with the Diplostylus in the Joggins 

 plant-bed, has evidently nothing to do with that genus. It is im- 

 perfect, but can hardly be supposed to be other than the caudal joint 

 (broken) of a Eurypterus or allied form. It is, as usual in that genus, 

 contracted at its origin, but swells out afterwards, in the manner of 



* Anchylomera, Typhis, Brachyscelus, etc. 



