CHEIRURUS. 63 



The specimens figured are destitute of body and tail ; perhaps our Devonian friends 

 can supply better examples. 



Locality. — Middle Devonian Limestone of Lammaton, Torquay (Mr. Pengelly's and 

 Mr. Vicary's cabinets, Mus. Pract. Geology). 



Cheirurus bimucronatus, March. PI. V, figs. 1 — 5 ; PI. VI, figs. 9 — 18. 



Paradoxtdes bimucronatus, Murchison. Sil. System, pi. xiv, figs. 8, 9, 1837. 



— — Milne-Edwards. Crust., iii, p. 343, 1840. 



Calymene speciosa, Hisinger. Leth. Suecica, 2nd suppl., t. xxxix, fig. 2, 1840 (not 



of Dalman). 

 Arges bimucronatus, Goldfuss. Neues Jahrbuch., p. 54 4, 1843. 

 Cheirurus — Beyrich. Ueber einige Bohmische Tril., pp. 18, 19, 1845. 



— insignis, Id. Ibid., p. 12, fig. I, 1. 



— — Barrande. Notice Preliminaire, p. 49. 1846. 



— — Id. Syst. Sil. de Boheme, pi. xli, figs. 1 — 13 (optime), 



1852. 



— speciosus, Salter. Memoirs Geol. Surv., vol. ii, pt. 1, pi. vii, figs. 4, 5, G. 

 Ceraurus Williamsii, M'Coy. Ann. and Mag. Nat. Hist., p. 408, 1849. 



— — Id. Pal. Foss. Woodw. Mus., pi. i, F, fig. 13, 1851. 

 Cheirurus bimucronatus, Salter. Decade 7, pi. ii, 1853. 



C. {Cheirurus) grandis, 8 — 10- uncialis. Glabella superne latior, sulco frontali et 

 oculari obliquis prope medium glabella terminatis ; lobis inferis trigonis {estate rotundioribus) 

 sejunctis. Gena glabella angustiores, oculis medianis, spinis posticis parallelis. Thorax 

 pleuris trituberculatis. Cauda parvula, utrinque pleuris tribus suboequalibus ad basin 

 brevisulcatis, apicibus robustis in estate arcuatis, scepe mucrone centrali brevi. 



Pew Trilobites are more common than this in the border-counties of England and 

 Wales, and few are so seldom found in a perfect state. We owe the beautiful specimens 

 here figured to the care and diligence of the Dudley collectors, who, following the good 

 example long ago set by Mr. John Gray, are patiently developing the shale specimens 

 which used to be neglected. It is found that the shale matrix preserves the fossils best. 

 Mr. Gray is still at work, and is the master of this art. Our good friend, Mr. C. Ket- 

 ley, of Smethwick, is hardly less skilful, and we are much indebted to both these gentle- 

 men. Mr. Allport, of Birmingham, Mr. E Hollier, jun., of Dudley, and others, have 

 lent us choice materials. We now know the whole of this species, which, when 

 first described, was one of the most obscure of all our Trilobites. It has a wide 

 range, from Caradoc to Ludlow Rocks inclusive. It is found in North Europe, 

 but not in America ; and it is an excellent type of the genus Cheirurus. Neither 

 unduly inflated in the head, nor greatly depressed, as in some of the Lower Silu- 

 rian species, it is a typical form, with glabella-furrows running partly and not com- 



