564 Reports and Proceedings 



A careful examination of the original specimens of JE7. mammatus 

 has enabled me to show that four out of the six specimens known 

 and referred by the late Mr. Salter to the genus Eurypterus are 

 plant-remains referable to the genus JJlodendron, or to fragments of 

 a large Equisetaceous plant, and that the two remaining parts appear 

 to belong to Jordan and von Meyer's genus Arthropleura, a non- 

 descript Crustacean (or, more probably, a gigantic Arachnide), only 

 known at present by a series of obscure fragments from Saarbruck, 

 from Manchester, and from Camerton Colliery, near Bristol. 



The ornamentation as well as the form of these pieces are totally 

 unlike any known Eurypterus. 



Of Eurypterus ferox I am now able to state that it is not an 

 Eurypterid, but is referable to Messrs. Meek and Worthen's American 

 genus Euphoheria, and that it is a gigantic Mtriapod, much larger 

 than our largest tropical living species of Julus or Centipede. This 

 is the second species of Myriapod occurring in the Coal-field of 

 Illinois, U.S., which has since al^o been obtained in England. 



Of the Merostomata only the sub-order Xiphosura remains to be 

 monographed, a task which I hope to complete during the present 

 year. 



At the beginning of this year I was requested by Eobt. Etheridge, 

 Jun., Esq., F.G.S. (of the Geological Survey of Scotland), to ex- 

 amine some specimens of Ceratiocaris from Lesmahagow, Lanark- 

 shire. Among them was one to which he specially drew my 

 attention, as it presented the novel appearance of appendages on 

 the under side of the caudal series of segments. These consist of 

 gill-like plates, depending freely from each segment. They are no 

 doubt analogous to those seen in Nebalia, which are supplementary 

 abdominal gill-feet. The discovery of these organs by Mr. Etheridge, 

 which occur also in several other specimens, does not in any way 

 alter the position of Ceratiocaris, but renders our knowledge of it 

 more complete. 



Since Mr. Salter's paper " On Peltocaris, a new genus of Silurian 

 Crustacea," was published in 1863 (Quart. Journ. Geol. Soc, vol. 

 xix., p. 87), I announced a second genus Discinocaris, in 1866 (see 

 Quart. Journ. Geol. Soc, vol. xxii., p. 503), also from the Llandeilo 

 flags of Dumfriesshire. Mr. Charles Lap worth, Mr, J. Wilson, Mr. 

 Kobert Michie, and others, have added several fine examples of this 

 type of Phyllopodous Crustacea. The largest of these is a portion 

 of a carapace from Dobb's Linn, Moffat, Dumfriesshire, and appears 

 to agree best with Discinocaris ; but instead of being a carapace the 

 size of a threepenny piece, like Discinocaris Broivniana, described 

 by me in 1866, this specimen, with its characteristic markings, gives 

 evidence of an individual 7 inches in diameter. Another specimen 

 of this same gigantic phyllopod was obtained from Moffat by Eobert 

 Etheridge, Jun., Esq., F.G.S., of the Geological Survey of Scotland. 



An entire carapace (of which three examples have been obtained), 

 from the Eiccarton Beds, Yads Lynn, near Hawick, makes us ac- 

 quainted with a new genus, for which the name Aptycliopsis is 

 proposed. 



