Palaeozoic Arachnida of North America, 



101 



Antkracomartus triangularis n. sp 

 Plate XI, fig. 6i; text fig. 58. 



The type and only specimen 

 of this species, No. 37968 of the 

 U. S. National ^Museum, shows like 

 the preceding species only the 

 dorsal surface on the obverse and 

 its mould on the reverse. The 

 specimen is black, but in some 

 places the black color is gone so 

 that it appears mottled with yellow. 

 On the same rock are impressions 

 of ferns. The body is much flatter 

 than in A. trilobitus. Total size 

 18.6 mm. Cephalothorax distinctly 

 triangular, 6.5 mm. long, 7.5 mm. 

 \^dde at posterior edge. Maximum 

 width of abdomen 11. 3 mm. Lines 

 of separation heavy, black. The 

 first tergite completely covered by 

 the cephalothorax. An interesting 

 feature represents the shape of the 

 seventh and eighth (sixth and se- 

 venth visible) tergites. 



Found in the Upper Coal Measures 

 of Joggins Mines, Nova Scotia. 



Fig- . 

 Figure ^S.—Anthracomarhis trian- 

 gularis n. sp., from the Upper 

 Coal Measures, Joggins Mines, 

 Xova Scotia, holotype, U. S. N. M. 

 4 



r 



No. 37968, dorsal surface. X 



Family Eophrynidae. 

 Key to North American Genera of Eophrynidae. 

 Cephalothorax triangular, elevated in the middle, sloping gradually 

 in all directions, not sculptured Trigonotarbus Pocock 



+ Cephalothorax sculptured 2 



Cephalothorax triangnlar, wider than long, its surface divided 

 into hexagonal fields. Abdominal tergites 9 



Areomartus n. gen. 

 + Cephalothorax triangular, longer than wide, \vith a median 

 longitudinal crest in its posterior half. Abdominal tergites 8 



Trigonomartus n. gen. 

 Areomartus n. gen. 

 With the characters given in the key. Genotype A. ovatus n. sp. 



