536 Dr. H. Woodward — On the Genus Cyclus. 



it with that already figured in this Magazine (1870, Woodcut, 

 p. 558), from the collection of Mr. Joseph Wright of Belfast, and 

 obtained by him from the Carboniferous Limestone of Little Island, 

 Cork, and, making allowance for some slight variation between the 

 two specimens, due to their different state of preservation, I am 

 compelled to conclude that they are both referable to the same 

 species, namely, C Jonesianus. 



Dr. Young's specimen measures 8 millimetres in length, 7 mm. in breadth, and 

 4mm. in height. The carapace, which is finely granulated all over its surface, is 

 divided along the anterior border into five rounded lobes of nearly equal size, form- 

 ing a semicircle, reaching almost to the margin of the shield. The middle area of 

 the carapace, enclosed by these five encircling lobes, is divided down the centre by 

 the dorsal line, thus forming a pair of oblong, somewhat pentagonal lobes, separated 

 only by the median line ; behind these, again, is a lesser unpaired subtriangular 

 lobe, with its base directed forwards and having a raised rounded boss in its centre. 

 The hinder and greater half of the carapace is occupied by two large lobes, forming 

 together a semicircle, but divided down the mesial line by the well-marked dorsal 

 ridge which extends to the posterior border. The upper and more central part of 

 each lobe is marked by a slight semicircular furrow dividing faintly this inner and 

 more elevated portion of the shield from the lower and outer encircling border. The 

 two minute depressions observed in Mr. "Wright's specimen, one on either side of the 

 dorsal ridge, at the vertex of the shield, are not visible in Dr. Young's specimen, 

 being probably covered by a shelly layer, which had been removed in Mr. Wright's 

 Irish example. 



Formation. — Carboniferous Limestone. 



Localities. — Little Island, Cork ; and Trearne, Beith, Ayrshire. 



2.— Ctclus kadialis, Phillips, sp. PI. XV. Fig. 2. x 4: times 



natural size. 



Agnostus radialis, Phillips, 1836. Geol. Yorks. vol. ii. t. xxii. fig. 25. 

 Cyclus radialis, H. Woodw. and J. W. Salter, 1865. Cat. and Chart Foss. 



Crustacea, p. 15, fig. 14. 

 Cyclus radialis, H. Woodw., 1868. Brit. Assoc. Rept. p. 75, pi. ii. fig. i. 

 Cyclus radialis, H. Woodw., 1870. Geol. Mag. Vol. VII. PI. XXIII. 



Figs. 2 and 2a, p. 557. 



Dr. John Young, F.G.S., of the Hunterian Museum, Glasgow 

 University, very kindly submitted the small specimen to me, which 

 is drawn (PI. XV. Fig. 2), as probably a new species; but, after 

 comparing it, I am of opinion that it should be referred to Phillips's 

 Cyclus radialis. The specimen, which is imperfect around the 

 border, is from the Carboniferous Limestone of Beith, Ayrshire, and 

 is attached to a portion of a frond of Ftilopora or Fenestella. 



The carapace measures 6 millimetres long, by 5 mm. broad. As 

 it is less perfect than the type it is needless to give a fresh descrip- 

 tion of it here. 



Formation. — Carboniferous Limestone. 



Localities. — Little Island, Cork ; Bolland and Settle, Yorkshire ; 

 Trearne, Beith, Ayrshire ; Vise, Belgium. 



3. — Cyclus Scotti, H. Woodw. PI. XV. Fig. 3. x twice nat. size. 



Cyclus Scotti, H. Woodw., 1893. Geol. Mag. Dec. III. Vol. X. p. 28 

 (Woodcuts A, B). 



Notwithstanding the difference in the size between Mr. Scott's 

 specimen from the Coal-measures of Bacup and Fig. 3, from Mr. 



