Br. H. Woodward — On the Genus Cyclus. 531 



Having, through the kindness of Prof. John Young, M.D., F.E.S.E. 

 (Eegius Professor of Natural History in the University of Glasgow), 

 and Mr. John Young, LL.D., F.G.S., of the Hunterian Museum of the 

 University of Glasgow, been allowed to examine and figure another 

 of the late Dr. Eankin's specimens from Carluke — now preserved 

 in the Museum of the University (Plate XV. Fig. 8)— and being 

 also in possession of a long series of specimens obtained by the late 

 Mr. Henry Johnson, C.E., F.G.S., of Dudley,^ from the "Pennystone 

 ironstone," over the thick coal of the Staffordshire Coal-field, at 

 Coseley, near Dudley, 1 am desirous once more to call attention to 

 these very singular little Arthropods. 



PiQ, 1, — Cyclus Woodwardi, Eeed. The original specimen is in the "Woodwardian 

 Museum, Cambridge, and was obtained from the Carboniferous Limestone, 

 Settle, Yorkshire. Magnified f nat. size. 



By far the most important contribution to the genus Cyclus 

 recently published is to be found in the paper by Peach, entitled 

 " Further Researches among the Crustacea and Arachnida of the 

 Scottish Border."^ These specimens, writes Peach, "occur chiefly 

 as flat discs, or dome-shaped masses of radiating calculi which have 

 coalesced into a polygonal mosaic of calcareous plates. They vary 

 from 3 mm. to 10 mm. in diameter." .... "Being embedded in 

 shale they are more or less flattened, and apparently much in the 

 same condition as the Cyclus BanMni described by Woodward as 

 having been obtained from the Carboniferous (shales) of Carluke." 

 They are considered by the author to belong to one species, which 

 is, he thinks, different from any yet described. "A few of the 

 specimens exhibit the dorsal shield, which is plain or slightly 

 embossed ; while others only show the dorsal aspect of the borders, 

 the rest of the upper surface being broken away, exposing the ventral 

 or sternal arches, which radiate much as in Cyclus Bankini." .... 

 " From the fact that several of the Survey specimens exhibit limbs, 

 the radiating lines of the sternum are most probably the divisions 

 between the coxse, so that I am inclined to differ from Woodward 

 and to look upon the opposite end to what he does as being the 

 anterior." Then follows the specific description of Cyclus testudo, 

 Peach, from the Calciferous Sandstone series, Langholm. 



In October, 1886, I became aware, from a study of Mr. Henry 

 Johnson's collection of Cyclus, obtained from the clay-ironstone 



1 Purchased by the British Museum in 1886. 



2 Trans. Eoy. Soc. Edinburgh, 1883, vol. xxx. p. 511, pi. xxviii. figs. 9 

 and 9a, b, c, d. 



