Dr. II. Woochvard — British Carboniferous Cockroaches. 67 



Thorax. — The pvotliorax, or pronotum, is circular in outline in 

 front, the sides being slightly compressed and the posterior boi'der 

 rather incurved near the centre (in Fig. 3) ; but this incurving of the 

 posterior border is not seen in Fig. 2, so that it may be due to a 

 slight lateral compression of the pronotal shield in the former 

 specimen. In confirmation of this suggestion it may also be stated 

 that the one specimen (Fig. 2) displays no median suture (or ridge) 

 on the shield, whilst the other (Fig. 3), which is incurved on its 

 posterior border, is also distinctly marked by a sharp ridge down its 

 centre. Both specimens display the same indentation around a 

 central pyriform slightly raised, area (similar to that observable on 

 the pronotum in Plate II. Fig. 1). 



Length of the pi'onotum, 7-J mm. ; bi'eadth, 9 mm. The meso- 

 thorax is about 1 mm. broader than the metathorax ; they are nearly 

 of equal length and closely resemble each other in form, being 

 broader in front than behind, and indented upon the lateral margins, 

 to give attachment to the wings. Breadth of mesothorax 6 mm. ; 

 length 3| mm. ; breadth of metathorax 5 mm. ; length 3-| mm. 



The Abdomen consists of ten somites ; the first is narrower than the 

 rest, and the second is the longest; the whole measure 16 mm. in 

 length, and about 3 mm, or a little more in breadth. There is 

 evidence in Fig. 2 (uncovered with the needle-point, since figuring) 

 of epimeral pieces to the 7th, 8th, and 9th segments on one side, 

 which, repeated on the other side, would add 2 mm. to the breadth 

 of the abdomen, making the total breadth 5 mm. The cerci are 

 S mm. in length, the articuli cannot be seen ; they are broader in 

 the centre, curved and pointed at the extremities. 



Wings. — The wings are remarkably short in proportion to the 

 total length of the body, and the anterior ones are strongly arched 

 along the superior margin. The upper wings measure 11 mm. in 

 length, and the lower or under wings 10 mm. Breadth of upper 

 wings 5 mm., and of lower wings 4: mm. 



Owing to some slight difference in the lithological character of the 

 clay-ironstone composing these nodules, rendering them slightly 

 coarser in texture than that which enclosed Fig. 1, — or else, as is 

 more probable, tlie wings themselves were actually composed of 

 thicker chitine in which the more minute veins were less delicately 

 delineated ; — whatever the cause, it is certainly much more difficult 

 to decipher the venation of the wings in these specimens than in the 

 other examples figured above. 



We see in the upper wings, or tegraina, of both Figures 2 and 3, 

 one very prominent vein, traversing the whole length of the wing, 

 almost parallel with the superior margin ; this is evidently the 

 mediastinal vein. Only the very faintest traces of branches along 

 the superior border of this vein can be detected in Fig. 2, on the 

 right-hand wing. The anal vein can be made out pretty clearly in the 

 wings of both specimens (see PI. II. Figs. 2 and 3), it extends down 

 to about one-third the length of the inferior border of the wing. The 

 separation of the intermediate area into intei'no-median, externo- 

 median and scapular, is most difficult to follow. The interno-median 



