PHYLOBLATTA SULCATA. 113 



Archimylacris, sp. indet. Plate VII, fig. 6. 

 1911. Archimylacris, 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 and Locality. Base of Upper Coal Measures (Mynyddislwyn Vein, 

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



Genus PHYLOBLATTA, Handlirsch. 

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



Generic Characters. Tegmina elliptical, t\vo-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. GeraUattina (Aphthoroblattina) sulcata, Bolton, Quai't. Journ. G-eol. 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 16 mm., 

 the perfect wing being probably about 45 mm. long, and 2223 mm. wide. If this 

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

 15 



