50 



TERRESTRIAL CARBONIFEROUS AEACHNIDA. 



anterior width. The posterior borders of the seventh and eighth distinctly angled 

 in the middle line. On the seventh, eighth, and ninth terga a distinct integumental 

 groove running from the anterior to the posterior border and representing 

 apparently the external of the two pairs of grooves seen in other species, the 

 internal grooves dividing the terga into three definite areas being invisible in 



G. angulatus. 



First sternal plate of opisthosoma much longer than the second or third in the 

 middle line ; its posterior border emarginate ; the second short, its median length 

 about one-fourth its posterior width, narrower laterally, its anterior border fitting 

 into the emargination of the posterior border of the first ; the third only a little 

 longer than the second in the middle line, its anterior borders lightly biangulate, 



Fig. 19. — Geraphrynus angulatus, sp. n. ; dorsal surface with appendages, four 

 times nat. size. — Coal Measures ; Coseley, near Dudley. Wheelton Hind 

 Collection. 



Fia. 20. — Ventral surface of 

 the same. 



its median length about half that of the fourth ; the fourth, fifth, and sixth 

 increasing gradually but slightly in length, but the sixth only a little longer than 

 the fourth and barely two-thirds the length of the seventh. 



Leg of first pair with trochanter, femur, patella and tibia about equalling the 

 carapace in length ; the same segments of the fourth leg equalling the last five 

 terga or four sterna of the opisthosoma; the spiniform process on the distal 

 inferior edge of the femora and patellar apparently smaller than in other species 

 (c. g. G. Idndi) where they are shown. 



Measurements in mm. — Total length 16 ; median length of carapace 6, width of 

 latter 6 - 5 ; median length of opisthosoma about 10 ; width of the latter 7"5 ; length 

 of sternal surface of opisthosoma 13; length of first leg from base of trochanter to 

 end of tibia 5 - 5 ; the same segments of the fourth leg 9 - 5. 



