ON SOME OF THE FOSSIL TETTIGID^. 169 



they formed part of the castings from the stomachs of 

 some large birds, the horny or chitinoiis substance of 

 which is weh known to resist the action of many powerful 

 solvents, and thus, as in the rejected pellets of the 

 owls, they are voided unaffected by the juices of the 

 stomach. 



Prof. Westwood tells us that one of the best beetle- 

 traps is a toad, in the excrement of which reptile 

 entire specimens of "ground-beetles" may often be 

 found. 



Eh^etic Fokmation. 



. Schambelen, in the Swiss canton of Aargau, is 

 situated on the edge of the Ehsetic rocks on the 

 river Keuss. The fossiliferous strata consist of marly 

 and slaty rocks, which stand out as cliffs. They are 

 exceedingly friable, and by the action of wind and 

 rain they speedily disintegrate into small fragments, 

 which are sold for manure. The beds, originally 

 horizontal, are now nearly perpendicular in position. 

 One, a blackish marl, contains a remarkable number 

 of ants, Hemiptera, and other insects, partly aquatic. 

 There is also a fresh-water formation, but interposed 

 between marine strata, containing ammonites, penta- 

 crinites, shells, and fish. It is remarkable that the 

 still-water deposits (although, so far as insects are 

 concerned, consisting chiefly of elytra and wings 

 even), nevertheless, retain parts of the original organic 

 matter, and leaves of trees may be detached from the 

 stones enclosing them (see Heer, vol. i. p. 6Q). 



The fossil species from Schambelen number 143, of 

 which 12 are Hemiptera, including Cercopidium morio, 

 C. minutum, both figured in my Plate F, and three 

 species of Jassidse. 



In some of the limestones at Durdlestone Bay, near 

 Swanage, belonging to the Lower Purbeck series, 

 there are numerous insect remains, which even retain 

 traces of colour ; but in Wiltshire, insects are mostly 



