Dr. H. Woodward — On a New Cavhoniferoiis Ewyptents. 483 



The above remarks are equally applicable to all the Crustacea 

 described in the present paper. Sometimes these calculi are 

 sporadic, at other times they fill the whole tests of the creatures, 

 forming an irregular polygonal net-work, which destroys the 

 character of the test and gives it a granulated appearance. Even 

 in this case the nucleus and radiations are observable." These 

 calcareous deposits are most carefull^^ figured by Mr. Peach in plate 

 ix. of his memoir, figs. 4cg and 4^. They agree exactly with those 

 observed in the specimen of Euryptems now under description. 



In a detached piece, obtained with and forming a part of this same 

 specimen, is preserved the left margin of four other body-segments 

 which must have been parts of the 8th, 9th, 10th, and 11th 

 segments, so that we only need evidence of the 12th segment and 

 the telson to complete our knowledge of this specimen. 



These posterior segments give clear evidence of becoming 

 narrower and deeper as they recede from the head — the 9 th 

 being about five times as broad as deep ; the 10th being about 

 four and a half times as broad as deep ; the 11th being about twice 

 as broad as it is deep. There is the mould of a raised longi- 

 tudinal subcentral ridge, one evidently of a pair of ridges no doubt 

 present on each of the posterior body-segments as seen in Eurypterus 

 remipes (De Kay) from North America. 



The fifth pair of broad spatulate swimming-feet answering to the 

 maxillee, or to the maxillipeds of the higher Crustacea, are not 

 preserved in this fossil ; but as they have been found with nearly 

 all the species of Eurypterus hitherto described, there is little 

 doubt that this form also possessed them when entire. Certainly 

 the other appendages reproduce with only slight modification in 

 their style of ornamentation those of the Russian, the American, 

 and the Lanarkshire Eurypteri ah-eady described and figured by 

 Hall, Schmidt, and myself. Certain delicate brown leaf-like bodies 

 can be observed lying on the left side of the head. There can be 

 no question that these are the remains of the branchiee, such as I 

 have figured from Lanarkshire, and such as are frequently found 

 lying detached on pieces of shale from Eskdale, and which have 

 been considered by Mr. Peach to have belonged to some form of 

 Arachnide ? 



Prof. Geikie indeed states that ''Mr. Peach's researches go to 

 show that the Carboniferous Eurypterus was almost certainly a 

 gigantic Arachnid and not a Crustacean. Some splendid specimens 

 of its scorpion-like combs and feet have been obtained from the 

 Lower Carboniferous rocks of the South of Scotland " (Geikie's 

 Text-Book of Geology, p. 724, Second Edition, p. 723.) 



The scorpion-like combs I have not seen, but I cannot for a moment 

 doubt that the feet of this specimen are those of a true Eurypterid, 

 and although the pair of swimming-feet are not preserved, the form 

 of the body-segments and their squamate ornamentation proves that 

 this was a true aquatic form, and that the fragmentary leaf-organs 

 lying beside it were remains of its branchial lamellee. 



Of course — if the hranchiated aquatic forms of the Merostomata, 



