104 Henry Woodward — 07i British Fossil Arthropoda. 



composition, and with the addition of the physical details furnished 

 by the peculiar changes in its mode of crystallization exhibited by 

 Staurolite. Whether we have in either case the means of measuring, 

 even to a certain extent, the amount of alteration undergone by the 

 parent rock, it would be rash to say ; but the facts given are sug- 

 gestive, and seem to tend that way. 



I may, before leaving the subject, remind readers of the Geological 

 Magazine, that Staurolite has never been found out of strongly 

 metamorphic rocks, nor has it ever, I believe, been found, as Anda- 

 lusite has been said to be, in granite. I give below two analyses of 

 Staurolite from Brittany, by Jacobson, which I have borrowed from 

 those given in Phillips's Mineralogy (1852 edition, p. 283).^ 



ANALYSES. 





a. 



b. 



Silica 



. ... 39-19 



40-35 



Alumina 



. ... 44-87 



44-2'2 



Red oxide of iron 



. ... 16-09 



15-77 



Ox. mangan 



. ... 0-17 



0-10 



Magnesia 



. ... 0-32 



— 



V. — On some supposed Fossil Eemains of Abacenida (?) and 



Mtbiopoda from the English Coal-measukes. 



By Henry Woodward, F.G.S., F.Z.S., 



Of the British Museum. 



IN the fourth part of my Monograph on the Mekostomata, pub- 

 lished in last year's volume of the Palseontographical Society's 

 annual issue,^ I drew attention to two very singular fossil remains 

 which had been somewhat doubtfully referred by Mr. J. W. Salter to 

 the genus Eurypterus. A portion, at least, of the remains referred by 

 him to Eurypterus ? mammatus are really plant-remains (as shown 

 by Mr. Carruthers, op. cit., p. 168), whilst the remainder must, for 

 the present, be classed with M. Jordan's Artliropleura armata, from 

 the Coal-measures of Saarbruck, Rhenish Prussia, a very anomalous 

 Crustacean (if it be a Crustacean at all, which I greatly doubt), but 

 which is certainly not a Eurypterus. 



With reference to Eurypterus ferox, I think (upon comparison) it 

 may with propriety be referred to the Myriopoda under Messrs. 

 Meek and Worthen's genus Euphoberia. 



Species 1. — " Eurypterus ? mammatus," Salter ; H. Woodward, 

 Pal. Soc. Mon. 1872, part iv., p. 163, pi. xxiv., figs. 2-6. 



Eurypterus {Arthropleura ?) mammattcs, Salter, 1863. Quart. Journ. Geol. Soc, 

 vol. xix., p. 84, figs. 1-7. 



This species was determined by Mr. J. W. Salter in 1863, from 

 fragments referred by him *' to the head (see Woodcut, Pigs. 1, 2, 

 and 3), to the lateral portions of the body-segments, and parts 

 nearer to the tail (Woodcut, Figs, 4, 5, 6, and 7) ; but of the central 

 surface of the carapace, of the eyes, or of the appendages, nothing 

 is known." 



The first fragment was discovered by Mr. Gribbs, the intelligent 



' The locality "Quimper" given for Staurolite in this work is undoubtedly 

 erroneous. 2 p_ ig3_ 



