PHILLIPSIA. 43 



Free thoracic segments unknown. Pygidium much broader than long, very 

 strongly trilobed ; axis elevated, consisting of twelve coalesced somites ; each 

 ring very strongly ridged, and each ridge ornamented with a line of minute 

 tubercles ; side pleuras nine in number, rather broad for half their length, and 

 minutely ornamented, but becoming fainter for the latter half, and dying away near 

 the margin, which is almost smooth. Length of pygidium 6 mm., of axis 5 mm., 

 breadth of tail 9 mm., breadth of axis 4 mm. 



Formation. — Carboniferous Limestone. 



Locality. — Bolland, Yorkshire. 



There are four examples of this small species in black Carboniferous Lime- 

 stone from Bolland, part of the Gilbertson collection preserved in the British 

 Museum (Natural History). Each specimen of a pygidium has also a detached 

 glabella preserved together in the same piece of matrix. There seems no doubt 

 that the heads and tails originally belonged to the same individuals. They are 

 quite unlike the ornamented pygidia of other species of Phillipsia, being broader 

 and shorter, and more delicately ornamented, the pleurge of the tail in particular 

 being very peculiarly marked in their decoration and form, and in the break in their 

 character midway. They appear to be worthy of specific recognition. 



21. Phillipsia scabea, H. Woodw., sp. nov. PI. IX, figs, ha, b. 



This species is based upon a head-shield and two pygidia from the Carboni- 

 ferous Limestone, Vallis Vale, Frome, Somerset, preserved in the Museum of 

 Practical Geology, Jermyn Street. 



These are the first remains of Trilobites I have received from the Carboni- 

 ferous Limestone of the south-west of England. 1 



The head-shield is 12 mrn. in breadth by 8 mm. long. The glabella is promi- 

 nent, rounded in front, but not overhanging the raised anterior border of the 

 cephalon ; three oblique furrows mark the sides of the glabella, the front furrow 

 being nearly in a line with the anterior angle of the eye ; the basal lobe is large, 

 obtusely triangular in form ; neck-lobe 1 mm. deep, divided by a shallow furrow 

 from the glabella; pleuras of neck-lobe extending for three-fourths the breadth 

 of free-cheeks, and terminating acutely along their posterior margin ; lateral 

 border of glabella narrow, but expanding into a moderately broad margin in 



1 Mr. E. H. Valpy, F.G.S., Enborne Lodge, Newbury, informs me that he discovered a bed of 

 shale of Carboniferous age with Trilobites in an excavation made for the Eifie-butts on the top of 

 Black Down, on the Mendip Hills, Somersetshire. They were associated with Entomostraca. 



