AEACHNIDA. 



401 



pairs of stigmata. The posterior border of the abdomen 

 carries four short spines, and the long and slender maxillary 

 palpi do not seem to have been chelate. This singular form 

 was described by Dr Henry Woodward from the Coal-meas- 

 ures of Dudley, and is believed by him to be most nearly 

 allied to the recent Phrynus. Arthrolycosa, from the Coal- 

 measures of Illinois, seems to have chelate maxillary palpi, 

 while the abdomen is distinctly segmented, and consists of 



Fig. 252. A, Eophrymis Prestvicii, viewed ventrally, and somewhat enlarged Carbonifer- 

 ous (after H. Woodward) ; B, Architarbiis subovalis, enlarged four times, and viewed from 

 below Carboniferous (after H. Woodward). 



seven somites. It is apparently allied to Tlielyphonus, though 

 showing resemblances to the Phalangidce. 



Another comprehensive type, with alliances to both Phry- 

 nidce and Phalangidce, is the Architarbus of the Carboniferous 

 rocks of North America and Britain. In the A. subovalis of 

 the latter region, the anterior portion of the body is com- 

 posed of amalgamated somites (fig. 252, B), carrying four 

 pairs of legs and a pair of palpi, the form of which is un- 

 known. Behind come four narrow somites, followed in turn 

 by three very wide segments, forming together nearly half 



VOL. I. 2 C 



