112 John Young — On Ortonia carbonaria. 



their legs attached. At any rate our fossil is certainly distinct from 

 the genus Arthropleura of Jordan and von Meyer, which is almost 

 beyond doubt a Crustacean." ' 



After carefully examining the English U. ferox of Mr. Salter, and 

 comparing it with Messrs. Meek and Worthen's figure and descrip- 

 tion, I am disposed fully to agree with the latter writers, and to refer 

 it to the Myriopoda and to their genus Euplioheria, feeling certain 

 that it has no relation whatever with SJurypterus. 



The reasons why JE. ferox should no longer be retained with the 

 JEurypteridce may briefly be stated : 1. We know of no undoubted 

 JEurypterus with body-segments ornamented with spines or tubercles 

 like those of E. ferox. 2. The segments, when seen in series, are 

 never (in Eurypterus) of a uniform size, but invariably diminish, as 

 regards their breadth, from the seventh segment towards the telson. 

 "With the single exception of Eurypterus ScouJeri (a most aberrant 

 form of the Eiirypteridm), all the members have the segments but 

 very slightly arched, and (save in the three most posterior segments) 

 always much broader than long. 



We may therefore consider Mr. Salter's Eurypterus ? ferox as 

 excluded from the genus Eurypterus, and also from Jordan's genus 

 Arthropleura, and may refer it with considerable confidence to 

 Messrs. Meek and Worthen's Myriopodous genus Euplioheria. 



Formation. — Coal-measures ; Clay-ironstone. Localities. — Coal- 

 brookdale, Shropshire ; Tipton, Staffordshire. Foreign Localities. — 

 Coal-measures, Grundy County, Illinois, U.S. America.^ 



VI. — ^NoTE ON A Carboniferous Species of Ortonia. 

 By John Young. 



THE new species of Fossil Tiibicolar Annelides, from the Lower 

 Silurian strata of America, figured and described by Prof. 

 H. A. Nicholson in the October and February Numbers of the 

 Geological Magazine, has tended to throw light upon a closely 

 allied form found in the Carboniferous Limestone strata of the West 

 of Scotland. This species, as far as I am aware, has not hitherto 

 been figured or described. 



Several years ago, when I discovered this form, I was struck by 

 its general resemblance to a small Tentaculites ; but as my specimens — ■ 

 which are well preserved — showed that they had been attached to 

 other organisms, chiefly to spines of ProductcB, I saw that it could 

 not be in any way related to the free unattached forms referred to 

 that genus. I therefore retained it amongst the Serpidce. I am now, 

 however, satisfied that, if not identical, it at least is very closely 

 related, to Prof. Nicholson's genus Ortonia, and especially to his 

 0. minor, described and figured in the February Number of the 

 Geological Magazine. I am the more inclined to this opinion, as 

 I see that Prof. Nicholson does not now make the cellular structure, 



1 Op. cit. p. 558. 



2 The author desires to record his thanks to the Council of the Palseontographical 

 Society for granting him permission to use the woodcuts which illustrate this paper ; 

 which is, to a large extent, reprinted from his Memoir on the Merostomata in the 

 1872 volume of that Society's publications. 



