392 W. B. K King — A New Trilohite 



water conditions, there was a migration of more open water forms 

 into the area. 



The calcareous beds are probably on the same horizon as the Botany 

 Beds of the Middleton in Teesdale district, the fauna of which 

 Professor Garwood considers to he "the highest truly marine fauna 

 yet met with in the North of England ".^ Although the fauna of the 

 Shunner Fell Beds is in many respects unlike that of the Botany 

 Beds, the want of similarity is probably due to a difference in the 

 conditions of the sea at the time of deposition, rather than to any 

 great difference in age. The presence of a well-marked marine 

 horizon high up in the Millstone Grit on this area is of interest, as it 

 tends to support Professor Garwood's view that the fauna of the 

 Botany Beds migrated from the south-west or west. 



The Trilobites are found throughout the calcareous beds, but are 

 best preserved in one of the more massive limestone beds, marked A 

 in the section (Fig. 1). They are found in many stages of growth, 

 but appear to belong to one species. At first sight they resemble 

 PMlUpsia michicaldi (Fischer), but on close examination they are 

 found to be a species of Griffitliides. It would seem that this is one 

 of the highest horizons at which Trilobites are found in England, and 

 the forms might be expected to be somewhat modified. The 

 specimens have been shown to Dr. H. Woodward, and he considers 

 them to belong to a new species. As they are particularly well 

 preserved and many complete specimens have been found, there is 

 ample material from which to describe the species. 



Geipfithides Shunnekensis, nov. sp. (Plate XXXlI.) 

 General outline, elliptical. 



The measurements of an almost perfect specimen give the 

 following results : — 



Total length . 

 Greatest breadth 

 Length of head 

 Length of thorax 

 * Length of pygidinm 



Head semi-oval, nearly as long as broad. 



Glabella inflated, pear-sliaped, expanded anteriorly, narrowing 

 posteriorly, where it is elevated. The surface (when the original 

 shell is preserved) is ornamented with fine granules ; these are 

 relatively larger in the young stages. When the shell is removed 

 the surface appears perfectly smooth, although a few specimens 

 show two slight undulations, which may mark the position of 

 degenerate glabella furrows. 



The basal lobes are well defined, triangular, and smooth. 



The neck furrow is deep and curves in its central portion towards 

 the glabella. The neck ring is broad and swollen, and is ornamented 

 with one central tubercle and small granules, which are larger and 

 more distinct on the posterior margin. 



The fixed cheeks are narrow, with well-marked raised lobes at the 

 eyes. The free cheeks have a small smooth raised portion, but the 



■■ E. J. Garwood, Quart. Journ. Geol. Soc, vol. Ixviii, p. 543, 1912. 



