30 TERRESTRTAT. CARBONIFEROUS ARACHNIDA. 



leno-th is about 15'5 iinii., the opistliosoiim l)eii]g 0'5 mm. niid the prosoma G mm., 

 the width of l)oth i-cgions l)eiiig about o mm. There is a distinct spiuiform 

 process at the anterior extremity of the carapace as in certain recent forms, e. g. 

 LahocMrus. 



In Dr. Moysey's Collection there is a specimen from the Shipley Claypit with 

 the dorsal side exposed (PL II, fig. 3). The anterior portion of the carapace is 

 broken away, showing vaguely the coalesced coxae of the chelas and the distal 

 portion of the right chela. Behind the posterior border of the carapace there is a 

 triangular plate which I regard as the posterior sternal plate of the prosoma, the 

 exposure of which suggests that the overlying dorsal area was membranous ; on 

 each side of it may be seen the coxge of the legs of the last pair. Nine terga of 

 the opisthosoma are clearly discernible, but the three terminal segments of this 



Fig, 9. — Gevalimira hritannica, sp. n. ; restoration of ventral surface, three times nat. size. — Coal 

 Measures ; Coseley, near Dudley. W. Madeley Collection. 



region are vaguely defined; they appear, however, to be comparatively large both 

 in length and width ; the post-anal fiagellum is not preserved. Both the carapace 

 and the terga and lateral membrane of the opisthosoma are granularly coriaceous. 



Measurements in mm. — Total length about 20; length of opisthosoma 13, its 

 length, excluding the last three segments, 10, its width 6; length of chela, 

 excluding coxa, 7. 



This specimen is a little larger than the type and has the chelre decidedly longer. 

 The difference in length, however, both of the body and the chela, may be attribut- 

 able to age ; and since the males of recent species very commonly have the cheloe 

 much longer than they are in the females, it would be rash to attach specific 

 importance to the difference observed, even if the type specimen Avere known to 

 be fully adult. 



