154 ME. H. BOLTON ON INSECT-REMAINS [Feb. I9II, 



raised median portion was incurved and shorter than the sides. 

 The whole outer margin was thickened. 



Affinities. — The appearance presented by this pronotum some- 

 what suggests the prothoracic shield with wing-like expansions 

 of Lithomantis carbonarius} The resemblance to that species is 

 little more than superficial : for, while in Dr. Woodward's species the 

 lateral lobes are veined like the wings, in this case there is no trace 

 of veins, the surface being covered with longitudinal wrinkles, nor 

 is there any clear evidence of a rostral prolongation. On the other 

 hand, the recent Mantidae and Lithomantis seem alone to possess 

 this form of prothoracic shield, so far as I have been able to 

 determine. Certainly it is not present in any fossil member of the 

 blattoids, nor have I seen anything suggestive of it among the 

 pronota of recent cockroaches. If the pronotal shield were of an 

 undoubted mantid type, one would naturally turn again to the wing- 

 impression, expecting to find its blattoid determination erroneous. 

 The fact, however, that the two central main veins throw off their 

 branches in opposite directions effectually disposes of any possibility 

 of affinities with Lithomantis. That the prothoracic shield is that 

 of a Lithomantis or allied form, which has been accidentally pre- 

 served in close contact with the wing of a blattoid, seems hardly 

 likely. I am more inclined to think that the pronotal shield and 

 the wing-fragment are parts of the same insect, and that future 

 discoveries in older rocks may indicate that the apparent Litho- 

 mantid appearance of the pronotum points to a common origin 

 for the blattoids and the mantids. 



Hemimylaceis obttjsa, sp. nov. (PI. X, figs. 4 & 5.) [Reg. 

 No. 24510.] 



A stout, obtuse, rounded right wing, 23 millimetres long and 14 

 broad. The wing lies in a soft fire-clay full of Stigmarian rootlets, 

 and is distorted by pressure. It has been fractured obliquely 

 across the lower third and along the anal furrow. 



The outer margin is well rounded, the inner, judging by the 

 course of the anal veins, being almost straight. The proximal 

 half of the sub-costal area is smooth, broadly triangular, and 

 11 millimetres long. The sub-costa is sunken, and passes in a 

 straight line from near the middle of the wing-base to the outer 

 margin, forking into two short branches just before reaching the 

 latter. On its outer side it gives off near the base two short 

 branches, the outermost of which forks once, and the inner twice, 

 before reaching the margin. Owing to the perfectly straight course 

 followed by the veins, the sub-costal area is long, nearly equal to 

 two-thirds of the length of the wing in fact, and separable into a 

 basal smooth area, and a distal one crossed by few veins. 



The radius is large, much divided, and reaches distally almost to 

 ■the apical point. The lower half is characterized by a regular 



1 H. Woodward, Q. J. G. S. vol. xxxii (1876) pp. CO-65 & pi. ix, fig. 1. 



