BRITISH FOSSILS. 



Decade XI. Plate V. 



STAUEOCEPHALUS MURCHISONI. 



[Genus STAUEOCEPHALUS. Barrande, 1847. (Sub-kingdom Articulata. 

 Class Crustacea. Order Trilobita. Family Cheiruridse.) Head cruciform, with long 

 clavate glabella, greatly swelled in front into a hemispheric lobe, the base narrow 

 cylindric, with three pairs of furrows. Cheeks convex, with pedunculate eyes and serrate 

 margin. Facial suture ending on the external margin. Body rings 10, without pleural 

 grooves, pointed. Tail of few segments, the apices of the pleurae free. Barra7ide.'] 



Diagnosis. — S. ovatus, tuberculosus, oculis remotiusculis, margini 

 genarum spinoso. Cauda quadrata, pleuris omnibus cequalibus retrorsis 

 parallelis, haud divaricatis. 



Synonyms. Siauroeephalus Murchisoni, Barrande (1852), Syst. Sil. 

 Boheme, pi. 43, fig. 28-32, S. Murchisoni, Salter, iu Siluria, 2nd ed. 

 1859, p. 540 ; Id., Morris's Catal, 1854, p. 115. 



One of the most curious, though not most conspicuous, of our 

 British species. The globular head, or rather glabella, set on its 

 narrow stalk-like base, the gibbous cheeks, projecting eyes, serrate 

 border, and spiny combJike pleurae and tail, combine to give an 

 extravagant and unusual appearance to the fossil. It is seldom 

 found perfect. But the skill of the Dudley naturalists has long- 

 been exercised on it, and specimens are now to be found in many 

 cabinets. Mr. Hollier's specimens are the principal ones jSgured. 

 Mr. Ketley has some fine ones, and our figs. 1, 2, are from the 

 Museum of Practical Geology. They were formerly part of Mr. E. 

 Davis^'s collection at Presteign. 



Description. — About an inch long, of which the gibbous head 

 occupies more than two-fifths. This is longer than broad, roughly 

 triangular in general outline, but not truly so. It appears rather four- 

 lobed, or like the heraldic ''fieur de lis," the truly globular front 

 occupying more than half the length of the glabella, and being at 

 least three times as wide as its semi-cylindrical base, from which it 

 is abruptly cut off by a transverse furrow ; the base is marked by 

 two distinct lateral lobes besides the neck furrow. The cheeks 

 reach forward about half way up this globular portion, and the 



[XL v.] 11 E 



