A. H. Sivinton — On Fossil Orthoptera. 339 



grass-like leaved aquatic plants. The tinder side of the left elytron 

 is seen with many of its veins intact, and I have succeeded in re- 

 producing the longitudinal framework (see Woodcut, Fig. 5). The 

 right elytron is present only as an impression. 



Fig. 5. Diagram of the longitudinal framework of the under side of the left elytron of 

 Oryllacris Ungeri, Heer, 



The surface of the mud tablet bearing the delineation of the 

 Gryllacris reveals to us the aqueous nature of the vegetation of the 

 locality where it once found its home and the nature of its food 

 plants. It has been restored as crawling on a specimen from its 

 associated herbarium, a kind of extinct pond-weed, or rather tassel- 

 grass (Buppia). Some scales and the vertebree of a small fish lie 

 on the stone just in advance of its head, in the original ; and assist 

 in elucidating and illustrating this page of its natural history. 



Although probably never gazed on by human eyes, this grass- 

 hopper was not devoid of ornament. It had spotted elytra or wing- 

 covers, and boldly blotched or perhaps coloured imder wings ; so 

 that while thus it recalls to our mind the most handsome group of 

 recent species of Gryllacris, it also connects them, as I shall en- 

 deavour to show, by an exposition of the venation of the elytra, with 

 more ancient Orthopterous forms that peopled our earth in the dim 

 and far-off Carboniferous ages. 



Corydalis Brongniarti, Audouin. Under side of right elytron, 

 see Plate XIV. Fig. 3. 



This species, before noticed, from the Coal-measures of Coalbrook- 

 dale, Shropshire, is preserved to us in a wing, presumably the left 

 elytron, of an Orthopterous insect, lying on the cleft nodule, with its 

 under surface, on which it very probably rested during its interment, 

 exposed. 



This specimen, previously remarkable for the delicate venation it 

 displays, acquires additional interest in a serrated vein that lies near 

 its base : with little doubt the active agent of an organ of stridulation, 

 similar to that possessed by the male house-cricket, and with Avhich 

 this insect effects its incessant "cree-cree." 



To begin with the venation of the wing. If we compare the 

 elytron of G. Ungeri, Fig. 5, with that of the modern Gryllacris, 

 shown on our Plate at Fig. 1, it is at once seen, that although the 

 venation has in each instance the same typical sub-parallel arrange- 

 ment of its longitudinal branches, in G. Ungeri the limbs 1 and 2 

 of the scapular vein lie closer together, are more parallel, and the 

 principal limb (2) forms an elhoio or obtuse angle before its middle 



