502 Dr. L. Moysey — Coal-measure Arthropods. 



a carapace which is not only perfect but uncrushed. Unfortunately 

 it is quite detached and isolated, hence it is impossible with any 

 scientific accuracy to ascribe it to any definite genus. Luckily, 

 however, another carapace was discovered in another ironstone nodule, 

 somewhat weathered and broken, but still capable of being compared 

 with the perfect example, with which it was found to agree so 

 closely that there can be little doubt as to their identity. Later, 

 by careful development, it was found that the weathered carapace or 

 prosoma was still attached to the opisthosoina of an Arachnid which 

 can in all probability be referred to Anthracosiro. 



The undamaged carapace is markedly dome- shaped, curving 

 gradually anteriorly, while it falls rapidly posteriorly, leaving a flat 

 central area between the domed portion and the straight posterior 

 border. The anterior border is marked by two lateral rounded 

 indentations, with slight-pointed prominences between, and an equally 

 small central prominence or rostrum ; the sides are rounded. 



There is a faint median ridge running over the anterior half of the 

 carapace, converted in the posterior half into a well-marked more 

 or less stellate depression, with well-rounded lips, and occupying 

 mainly the sharp downward posterior curve of the dome so that the 

 depression looks upwards and backwards. 



There is distinct evidence of a pair of protruding eyes, one on each 

 side of the faintly marked median ridge, about 2"5 mm. apart, and 

 placed on a transverse ridge running just in front of the stellate 

 depression. 



There are also to be noted several folds starting from the posterior 

 part of the stellate depression and running round towards the sides. 

 These, however, may be due to crushing. The whole surface is 

 ornamented with very minute tubercles which are more pronounced 

 in the posterior portion. 



Dimensions : antero-posteriorly 6 mm., transversely 6'75mra. 



Another isolated and uncompressed carapace has been obtained from 

 the same quarry, which appears to be identical, but is much smaller. 



Dimensions: antero-posteriorly 4mm., transversely about 4mm., 

 one side being embedded in. matrix. 



Figs. 7, 8, Anthracosiro fritschii, Pocock. The weathered carapace 

 shows well the posterior flat area, the stellate depression and an eye 

 on the left side, the rest of the anterior portion of the carapace being 

 destroyed. Some of the appendages are also present. The limb 

 emerging from beneath the carapace on the right side is probably 

 one of the fourth pair of appendages, that is of the second legs. 

 It consists of a short, distally dilated trochanter about '75 mm. long, 

 articulating distally with the long stout femur about 325 mm. in 

 length, which runs directly out from the long axis of the body; 

 running forward and at right angles to this is placed the patella, 

 2'5 mm. long; the next segment, the tibia, about equal in length 

 with the patella, lies curving inwards towards the head. The next 

 segment, the tarsus, lies in line with the last, is about the same length, 

 but is somewhat obscured. The distal segment, the pretarsus, is not 

 well shown. Embraced by the limb are the remains of four other 

 appendages not shown in the Figure. The maxillae on both sides, the 



