Dr. L. Moysey — Coal-measure Arthropods. 



501 



of a projecting swollen ring, with a slight depression on its most 

 prominent part, evidently forming a facet for articulation with the 

 next anterior segment. Behind this ring is a deep sulcus separating 

 the anterior from the posterior portion of the fossil. The latter 

 portion is quadrate, slightly broader than long, somewhat convex 

 from side to side, and gradually narrowing posteriorly. Its posterior 

 border is straight. It shows a distinct median ridge, extending only 

 half the length of the segment, and two lateral ridges which extend 

 fully to the posterior border. Anteriorly the lateral ridges are 

 connected with the median one by transverse ridges, which form the 

 posterior boundary of the above-mentioned sulcus. The specimen 

 measures 10-5 mm. long by 9 mm. broad. It is in all probability the 

 first segment of the post-abdomen, the articulatory facet being the 

 point of attachment with the last segment of the prseabdonien. 



Fig. 5. Abdominal segment of Eurypterus. Coal-measures : Brinsley, 

 near Eastwood, Notts. Twice nat. size. 



Tig. 5, Segment of a Eurypterus. This detached segment of an 

 Arthropod was found at Brinsley Clay-pits, in a small ovoid ironstone 

 nodule. It measures 17 - 5 mm. broad by 6 mm. long. Its anterior 

 border is slightly concave, and there is a line running parallel with 

 the anterior border, and curving round to run also parallel with the 

 lateral border, which marks off a space about 1*5 mm. wide, which is 

 smooth. The rest of the surface of the segment is slightly roughened, 

 but posteriorly, and laterally the roughening is exaggerated into 

 well-marked, irregularly distributed tuberosities. 



It is impossible from a single segment to allocate this Arthropod to 

 its proper genus ; but, provisionally, we may place it among the 

 Eurypterids. It has not, it is true, the scale-like ornamentation usual 

 to Eurypterus, but in the narrow abdominal segments of E. moyseyi 

 the scale-like ornament is found to degenerate into tuberosities, and 

 from its size the segment under discussion is probably one of these 

 posterior segments. 



FlG. 6. Carapace of Anthracosiro. Coal-measures : Shipley, near 

 Ilkeston, Derbyshire. Three times nat. size. 



Fig. 6, Head of an Anthracosiro. It is apparently very unusual, 

 at any rate in England, to obtain a specimen of the Anihracomarti 

 which shows either the head or the appendages in a perfect condition. 

 One specimen, however, from Shipley shows the dorsal aspect of 



