﻿24 BRITISH FOSSIL CRUSTACEA. 



28. Prof. E. M'Coy, in 1849, 26 and again in 1854, 33 thus classifies this group — " Ord. 

 Entoniostraca, Trib. Pcecilopoda. This group being distinguished from other Ento- 

 mostraca by having crustaceous,, didactyle, ambulatory, thoracic feet, as well as mem- 

 branous, respiratory, abdominal ones, is, I think, clearly the place for those remarkable 

 genera Eurypterus and Pteryyotus." He adds farther, " The tribe Pcecilopoda might be 

 resolved into two families — 1st, Limulidce — Limulus; 2nd, Eurypterida — Eurypterus, 

 Pteryyotus , Pellinurus. 



29. Prof. M'Coy 35 also figures and describes the head of Eurypterus cephalaspis, from 

 Kendal (PI. I e, fig. 21), a somewhat doubtful form. His Pteryyotus leptodactylus is 

 founded on the tail-spines of Ceratiocaris, as pointed out by Mr. Salter. 



Like Dr. Hibbert, 9 he attributes to Dr. Harlan (1835) the genus Eurypterus, which 

 was established by Dr. J. E. Dekay 4 in 1825. 



30. Prof. P. J. Pictet 34 (1854) places Eurypterus with the Copepoda, adopting 

 Burmeister's 24 description. In the Xiphosura he places Limulus, Halycine, Pellinurus, 

 and Pteryyotus. 



31. In Prof. Owen's 'Lectures' 36 (1855) we find the order Xiphosura placed in the 

 sub-class Entoniostraca, along with the orders Trilobita and P/iyllojjoda. 



32. Prof. A. E. Reuss, 37 in 1855, gives a description of what he considers to be a 

 new genus of Eurypterids, from the Coal Shale of Bohemia, preserved in the Prague 

 Museum. He names it Lepidoderma Imhoffi, but it is certainly a Eurypterus, judging, 

 not only from his beautiful plates, but also from a cast sent to us by Dr. Anton Eritsch. 



Fig. 3. Pterygotus problematicus, Agassiz [copied from Prof. M'Coy's figure in Lyell's ' Manual of Geology,' 1855 (5th edition).] 



33. Prof. M'Coy again, in 1855, 35 furnishes us with a classification and descriptions 

 of species of this group ; and in Sir Charles Lyell's Manual 38 he gives a restoration 

 of Pteryyotus problematicus, where he again expresses his belief in the close alliance 

 of Pteryyotus and Eurypterus, and of both these to the living King-crab, or Limidus. 



34. In the same year Mr. David Page 39 named various species, and offered a 

 restoration of Pteryyotus. He observed that " The Pteryyotus could be classed with no 



