60 TERRESTRIAL CARBONIFEROUS ARACHNIDA. 



of the second ; it has no laminae, hut bears two widely separated tubercles. A 

 pair of similar but larger tubercles is present on the elevated median area of the 

 six following terga. The second tergal plate is large ; its pleural laminae are 

 distinct, with their postero-lateral portion inclined outwards and slightly back- 

 wards. The pleural lamina? from the third to the seventh are widely extended 

 laterally and divided by a distinct sulcus into an external and internal moiety. 

 The median area of the terga is narrow as compared with the same area in 

 Anthracomartus. The median area of the eighth tergal plate is very long- and the 

 inner moieties of the pleural laminae are not differentiated. In this respect B. 

 carbonis differs from all the other members of the Anthracomarti hitherto 

 described ; and it is the elongation of the tergal plate which gives the charac- 

 teristic length to the opisthosoma. 



Genus MAIOCERCUS, nov. 



Characters as above (p. 59). 



Type Species. — -Maiocercus celticus, Pocock. 



Fig. 29. — Maiocercus celticus (Pocock); ventral surface of opisthosoma, nat. size. — Coal Measures; Ty'nybedw, 

 Rhondda Valley, S. Wales. 1 st. to 9 si., sterna of the first to the ninth somites ; 8 tg., ventral side 

 of median lamina of the last tergal plate visible on the dorsal side ; 9 tg., area regarded as the tergal 

 plate of the ninth somite ; 10 tg., anal operculum or tergal plate of the tenth somite ; imp., impression 

 (? coxal) marking the first and second sternal plates. From Geol. Mag. [4], vol. ix, p. 491. 



Maiocercus celticus (Pocock). Text-figure 29. 



1896. Eophrynus carbonis, F. T. Howard and T. H. Thomas, Trans. Cardiff Nat. Hist. Soc, vol. 



xxviii, p. 52, figs, a and b (nee Woodward). 

 1902. Brachypyge celtiea, E. I. Pocock, Geol. Mag. [4], vol. ix, p. 488, fig. 2 a. 

 1904. Brachypyge celtiea, A. Fritsch, Palseoz. Arachn., p. 41. 



The figure of the ventral surface of the opisthosoma of this species suggests 

 that the genus Maiocercus is much more closely allied to Anthracomartus than is 

 Brachypyge. The chief resemblance to Brachypyr/e lies in the scalloped edge of the 

 pleural laminae. There is no reason to suppose that the eighth somite is elongated 

 as in the latter. The posterior borders of the sixth and seventh sterna show the 



