PHYLOBLATTA SULCATA. 113 



Archimylacris, sp. indet. Plate VII, fig. 0. 



1911. ArcMmylacriSi sp. indet., Bolton, Quart. Journ. Geol. Soc, vol. Ixvii, p. 152, pi. vii, fig. 2. 



Type. — Impression of basal portion of left tegmen; Museum of Practical 

 Geology, Jermyn Street (no. 24508). 



Horizon ami Locality. — Base of Upper Coal Measures (Mynyddislwyn Vein, 

 Gellideg Level) ; near Maes-y-cwmmer, Monmouthshire. 



Genus PHYLOBLATTA, Handlirsch. 



1906. Phyloblatta, Handlirsch, Bull. U.S. Nat, Mus., vol. xxix, p. 738. 



Generic Characters. — Tegmina elliptical, two-and-a-quarter to two-and-a-half 

 times as long as wide ; costal area strap-shaped, rarely wide, and extending usually 

 to three-fifths or two-thirds the length of the wing; not expanded basally. Radius 

 with numerous branches, all of which reach the outer margin. Median with outer 

 branches only, reaching wing-apex. Cubitus large, much branched, and occupying 

 distal two-thirds of inner margin. Anal area large with numerous veins. Inter- 

 stitial neuration rugose leathery or much cross-wrinkled. 



Phyloblatta sulcata (Bolton). Plate VIII, fig. 1 ; Text-figure 36. 



1911. Gerablattina (Aphtkoroblattina) sulcata, Bolton, Quart. Journ. Geol. Soc, vol. Ixvii, p. 165, 

 pi. viii, figs. 1 — 3. 



Type. — Greater part of tegmen and its counterpart impression showing the 

 under surface only ; Museum of Practical Geology, Jermyn Street (nos. 24504 

 and 24505). 



Horizon and Locality. — Base of the Upper Coal Measures (Gwernau Level of 

 the Mynyddislwyn Vein) ; near Maes-y-cwmmer, Monmouthshire. 



Specific Characters. — Costal area broad ; subcosta strap-shaped, and extending 

 far out. Radius with six branches, occupying outer half of wing-apex. Median 

 with few divisions and occupying a small area of the wing. Cubitus united with 

 median at the base. Anal furrow well developed. Anal veins 5 — 8. 



Description. — The specimen comprises the greater part of a right tegmen, 

 showing the under surface, the counterpart impression being on a second piece of 

 black shale. An irregular narrow fringe of the wing-membrane has been lost 

 along the outer and inner margins, and the inner half of the wing-apex is also 

 missing. The length of the fragment is 35 mm., and the greatest width 1G mm., 

 the perfect wing being probably about 4-5 mm. long, and 22 — 23 mm. wide. If this 

 estimate is correct, the wing is short. Tegmina are usually at least two-and-a-half 

 15 



