H. Woodward — Ne2v British Fossil Crustacea. 559 



but the divisions whicli represent the costae are six, not seven, in 

 number in this species, and these anastomose together on the lateral 

 border, and diverge, not from a raised median ridge, but from a 

 broad \/-shaped central area (cardiac region?). One is reminded by 

 this Crustacean of the ajDpearance of Argulus, Bopyrus, and other 

 recent parasitic forms, and also of the disk-shaped Discinocaris, from 

 which, however, it differs in the ' eye-spots ' and costated shield. 



" For this new species I propose the name of Cijdus Ranhini, after 

 its discoverer." 



8. Oychcs {Halicyne) laxus, H. yon Meyer, PI. XXIII., Fig. 7 and 7a. 



9. Cyclus {iraUcyne)(^gmttm, H. von Meyer, PI. XXIII., Fig. 8 and 8a. 

 Hermann von Meyer has figured in the Palaeontographica, 1847, 



vol. i., p. 134, a small Crustacean head-shield under the name of 

 Halicyne agnota and a second species under the name of H. laxa, from 

 the Muschelkalk of Eottweil, in Germany. Goldfuss originally 

 figured it as Olenus serotinus; afterwards Munster referred it to 

 Limulus (Beitrage, 1841, Bd. i. t, v. f. 1). 



To both these conclusions Von Meyer demurs — to Limulus because 

 no eyes are visible ; and to the Trilohita, because none are found in 

 rocks older than the Carboniferous formation. 



The form of this head-shield is extremely like that of Agnostus ; 

 but the Agnostidca are confined to- the Lower Silurian strata, between 

 which and the Trias are the long intervening series of the Upper 

 Silurian, the Devonian, Carboniferous and Permian formations. At 

 the date of my report (1868), I was inclined to place Halicyne with 

 Bunodes, ITemiaspis, etc., among the aberrant forms of the LimuUdce, 

 being under the impression that it was only a part of a Crustacean, 

 probably a head-shield. Having now the advantage of a large series 

 of Carboniferous Cyeli with which to compare it, I feel no longer 

 any doubt about placing it with Cyelus, that being the older name. 



" Cyclus Brongniartianus," De Koninck.^ PL XXIII., Fig 9. 



This species is founded upon the hypostome of a Trilobite, most 

 probably of the genus Fhillipsia. As several specimens have been 

 forwarded to me so labelled, I take this opportunity to notice a 

 mistake, which I feel sure M. de Koninck would (if the occasion 

 had presented itself) have been one of the first to correct. 



We quote the following remarks on Cy cites from the British Asso- 

 ciation Eeport already referred to (p. 73) i — 



" In describing Cyclus radialis, M. de Koninck observes : — 



" There is no doubt this animal should be ranged with the Crus- 

 tacea, and in Milne-Edwards's order Tr Hob it a ahnormalia and battoidea, 

 near to Agnostus. 



" M. de Koninck also thinks it probable that the body of Cyclm 

 was soft and very contractile, that it was a parasite, and that the two 

 tubercles which we have called the eyes really covered those organs; 

 and, further, that the ribbed border protected the feet when the 

 animal was in repose. 



'■'■ We must differ from M. de Koninck in referring this form to the 

 Trilobita. If truly an adult, it must be placed near to Apus, with 



1 Descrip. des Anim. Foss. Terr. Cartonif. de Belgique. Liege, 1842-4, p. 592, 

 pi. lii., fig. 9, a, h. 



