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



Spec. char. — Carapace rounded, widtli somewhat greater than 

 length, broader and flatter in front, narrower behind, and with 

 a shallow rounded indentation at the centre ; having a broad and 

 well-marked flattened rim, followed by a corresponding shallow 

 depression around the lateral and posterior borders ; front border 

 tumid, with two (or more ?) raised rounded or ovoid prominences ; 

 carapace with a median dorsal ridge reaching from the posterior 

 border rather more than half way up the centre of the shield, 

 then bifurcating so as to embrace a triangular space, which widens 

 out to the anterior border ; carapace with moderately raised and 

 roundly swelling side-lobes' (not strongly ridged as in G. Scotti) 

 and with a pair of smaller oblong faintly raised lobes next the 

 median ridge. 



Appendages. — These consist of a pair of rather stout antennae 

 (probably the second pair of antennse), showing about four joints 

 on each side, the rest having been broken off. These are seen on 

 rigs. 4 and 5, and faintly on Fig. 6. 



Eyes. — Fig. 7 shows traces of two small eyes occupying the 

 same relative position as the one seen more distinctly in Fig. 8 

 (C. Bankini), and which appears to be pedunculated. 



The under-surface of the animal is partly exposed in Figs. 5, 6, 

 and 7 by the accidental removal of a part of the dorsal surface 

 of the carapace which remained adhering to the other half of the 

 clay-ironstone nodule when it was split open. 



In each of these examples, the converging bases of 6-7 pairs of 

 gnathopodites are seen uniting mesially behind the V-shaped oral 

 area (already referred to on p. 533) the median ridge behind 

 which may indicate the posterior prolongation of the straight 

 alimentary canal. 



In all these specimens, the bases of the limbs have a very close 

 agreement with G. Bankini (PL XV. Fig. 8). In Fig. 5 there is 

 a slight indication of the base of an appendage on the central 

 posterior border, which may have been part of a tail-spine ; but 

 it has not been observed in the others. "Wherever the surface is 

 preserved there is a fine granular ornamentation observable, more 

 especially in the hollow formed within the broad flattened rim that 

 surrounds the greater part of the shield. Fig. 7 is distinctly more 

 rounded in outline than the others, and may possibly belong to 

 another species. 



I have dedicated this form to the memory of the finder, the late 

 Mr. Henry Johnson, F.G.S., to whose labours as a geologist in the 

 Dudley area we are so largely indebted for our knowledge of the 

 fossil fauna and flora both of the Coal-measures and the Wenlock 

 Limestone. 



I must not omit to record my thanks to my son, Mr. Martin 

 Fountain Woodward, of the Biological Laboratory in the Eoyal 

 College of Science, for much valuable aid in the examination of 

 these minute specimens, and to my daughters for their excellent 

 figures in illustration of this and so many other papers which have 

 appeared in this Magazine. 



