NO. 2119. BRITISH FOSSIL INSECTS— COCKERELL. 481 



ably larger than G. anglica, and has the angle on outer margin of 

 elytra nearer the apex. 



OLIGOCENE INSECTS. 



All the Oligocene material before me comes from a single locality, 

 Gurnet Bay in the Isle of Wight. According to the labels on the 

 specimens, this locality belongs to the Bembridge series, but J. W. 

 Taylor * refers it to the Osborne series. J. Starkie Gardner ^ spells 

 the name Gurnett Bay, but on page 36 of the same work he writes 

 Gurnet Bay, recording Sequoia couttsiae Heer from the locality. 

 Handlirsch ^ places the Gurnet Bay deposit in the Lower Ohgocene, 

 along with that of Aix in Provence and the Baltic Amber. I have not 

 been able to determine any species as identical with those of Aix or 

 Baltic Amber. Compared with the amber fauna, that of Gurnet Bay 

 seems more decidedly temperate, with less suggestion of an oriental 

 or Australian fades. There is, however, the genus Mastotermes, now 

 known only from Australia. Kurt von Rosen,* when recording these 

 termites, speaks of the Gurnet Bay limestone as Middle Oligocene, 

 having apparently received this information from the British Museum. 

 It is necessary to learn more about the Gurnet Bay fauna before 

 expressing any positive opinion, but it seems possible that it is later 

 than the amber. 



The preservation of the specimens is most remarkable, as Brodie 

 long ago pointed out. There was absolutely no compression, and 

 when the rock is fractured so as to bisect an insect longitudinally, a 

 cast of its internal organs is presented, as shown in plate 65, fig. 7, A. 

 Many minute insects were preserved without losing their more delicate 

 parts, as is shown by a mosquito wing still carrying the scales. The 

 preservation was indeed similar to that of the amber insects, with the 

 important practical difference that the medium is entirely opaque. 

 There was perhaps a mud spring, with heated waters, into which the 

 insects feU, possibly overcome by gaseous emanations. The waters 

 were not themselves poisonous, as they were fuU of moUusks, and 

 many of the insect-bearing fragments of rock carry also multitudes of 

 a species of PhyUopod Crustacean, which is, I believe, the BrancMo- 

 podites described by Woodward.^ It would be difficult to exaggerate 

 the importance of this extraordinary deposit for an understanding of 

 the Oligocene life of England, and it is very much to be hoped that 

 more will shortly be learned about it, and more of the materials 

 collected will be described. 



' Monograph Land and Freshwater Mollusca British Islands, pt. 7, 1900, p. 411. 

 2 Monog. British Eocene Flora, vol. 2, pt. 1, 1883, p. 4. 

 > Die Fossilen Insekten, p. 677. 

 • ' Trans. Second Entomological Congress, p. 321. 

 6 Quart. Joum. Geol. Soc, Lond., vol. 35, 1879, p. 346. 



81022°— Proc.N.M.vol.49— 15 31 



