246 BRITISH FOSSIL CRUSTACEA. 



This new form is considered by Mr. Meek to be nearer Prestwichia anthrax than to 

 Bellinurus by reason of its anchylosed segments, but he considers that it differs from the 

 former in the comparatively small and quadrangular form of the glabella. 



Having compared Mr. Meek's figures of Euproops Dana with Professor Prestwich's 

 type specimen of P. anthrax, I am in a position fully to appreciate Mr. Meek's accurate 

 comparison of Euproops with that species. It seems hardly possible to do more than 

 separate them specifically. Of their generic identity I think there can be but little 

 doubt.] 



Species 2.— PRESTWICHIA ROTUNDATA :— H. Woodw. PI. XXXI, fig. 5. 



Limulus rotcndus, Prestwich, 1840. Trans. Geol. Soc, 2nd series, vol. v, pi. xli, 



figs. 5—7. 

 Prestwichia rotundata, H. Woodw., 1867. Trans. Glasgow Geol. Soc, vol. ii, 



p. 240, pi. iii, fig. 8. 

 — — H. Woodw., 1867. Quart. Journ. Geol. Soc, vol. xxiii, 



pi. i, fig. l,p. 32. 



The original specimen of this well-marked form of Palaeozoic King-crab is represented 

 by both the intaglio and relievo impressions preserved in a nearly circular nodule of 

 ironstone from Coalbrook Dale in the cabinet of Professor Prestwich, F.R.S. The relievo 

 side is figured on our plate (PL XXXI, fig. 5). 



Professor Milne-Edwards, who, at the request of Mr. Prestwich, examined this 

 interesting Coal-measure Crustacean at the time of its discovery, considered it to be a 

 distinct species, and he specially directed attention to the curious membrane-like border 

 of the thoracico-abdominal segments which connects them together. 



Other specimens have since been submitted to me from Dudley by Messrs. Charles 

 Ketley and E. Hollier; and from Kilmaurs, near Glasgow, by Mr. Parie. These 

 specimens add but little to our knowledge of the species, derived from the original 

 type-specimen, save that the Kilmaurs example has exceedingly elongated genal spines, 

 thus greatly altering the " circular outline " which suggested to Mr. Prestwich the trivial 

 name of rotundas. 



Mr. Baily writes ('Ann. and Mag. Nat. Hist.,' 1863, 3rd ser., vol. xi, p. 107) :— 

 " A species, closely allied, if not identical with Bellinurus {Limulus) rotundus, Prestwich, 

 sp., was also obtained at the same locality which had yielded B. regina and B. arcuatus 

 (Bilboa Colliery, Queen's County), but as it is scarcely perfect enough for description 

 I have preferred referring it, with a doubt, to that species." 



The head-shield is almost three times as broad as deep; the outline is nearly semi- 

 circular. The front margin of the glabella is arched, and just within its anterior border 



