14 CARBONIFEROUS TRILOBITES. 



Fig. 2 a, h, is a beautiful and very perfect specimen somewhat curved (as if not 

 quite unrolled) from the Carboniferous Limestone of Longnor, Staffordshire, the 

 original of which is preserved in the Museum of Practical Geology, Jermyn Street. 



This specimen, which is imbedded in hard limestone, has all the segments of 

 the body well preserved and united together, a rare occurrence in the Carboni- 

 ferous Limestone. The entire form is carefully reproduced in the outline, 

 fig. G. 



Two other nearly entire specimens, preserved on a piece of Carboniferous 

 " Rottenstone " from Matlock, Derbyshire, are represented in Plate I, fig. 4 a. 

 These are from the National Collection, Natural- History Museum, Cromwell Road. 

 Owing, however, to the soft nature of the matrix no very fine structure can be 

 observed, but in one of the specimens the hypostome (4 h) can be distinctly seen iii 

 situ. 



The specimen represented in Plate I, figs. 1 a, h, is interesting as the type of 

 Phillips' Asaplms raniceps, but I see no reason for separating this little head from 

 P. Derhlensis, although, from the fact of its being slightly flattened above, the 

 glabella appears to overhang the border more than in the normal forms. 



Two other heads in good preservation, figs. 3 and 5, the former from Settle, 

 Yorkshire (from the Woodwardian Museum, Cambridge), and the latter from 

 Castleton, Derbyshire (from the Cabinet of the Rev. E. O. de la Hey), exemplify 

 well the general character of the head of this species. 



Fig. 2 shows the finely faceted character of the eyes, as do also some admirable 

 specimens recently received from Prof. E. Hull, M.A., LL.D., F.R.S., from the 

 Geological Survey Museum, Dublin. 



After examination of all the specimens, and a careful consideration of General 

 Portlock's descriptions, I see no reason to retain P. Jonesii or P. Jonesii, var. 

 semmifera, M'Coy, as separate species, distinct from P. Derhicnsis. In this view, 

 I am happy to be in accord with my friend Prof. Morris, M.A., F.G.S., whose 

 carefully prepared ' Catalogue of British Fossils ' is still honoured with a place of 

 respect for the critical care displayed by its author in its compilation, although 

 now nearly thirty years old, and sadly in need of a new edition. 



The subjoined is the original description of PhiUijJsia Derhlensis, given by Mr. 

 W. Martin, in his Petrificatci Derhlensia (1809), and named by him Entoinolitlms 

 Oniscites [Derhiensis]} " This fossil," he says, "is not frequent in many parts of 

 the country. It is principally met with in the black marble at Ashford, where it 

 very rarely occurs in a perfect state ; the head and body being found, for the 

 most part, separate from each other." Martin describes it as " A petrified insect. 

 The original an Oniscus. The body oblong-ovate, broad and rounded at the head, 



1 ' Petrif. Derb.,' tab. xlv, figs. 1, 2. la the same work, on plate xlv*, figs. 1, 2, Martin repre- 

 sents what seems to be intended for Grijfitliides {Phillipsia) seminifcra, Phil, sp., hereafter described. 



