82 Mr. H. St. J. K. Donisthorpe on 



attached to individual specimens, those following an "I" or 

 "In - " are register-numbers of the Geological Department of 

 the British Museum. These numbers are all in one series, 

 but the letter " I" being subject to misapprehension, was 

 recently changed to lt In." It so happens that all the speci- 

 mens of the Brodie Collection (purchased in 1898) are denoted 

 by numbers following " I," and that those of A'Court Smith 

 Collection (though purchased in 1883) were registered later 

 under numbers following "In." Specimens from Mr. Hooley's 

 collection bear numbers following " H." The numbers in 

 brackets, with or without a letter, are those of my working 

 list. 



A large proportion of these insects belong to the Formicidae, 

 and I hud that the so-called Formica and Camponotus are 

 really species of Oecophylla. There are no specimens o£ 

 JUynuica, but one ant, which has " Myrmica" written in 

 pencil on the matrix, belongs to a new genus. Several 

 specimens of a large wing marked "Wing of Syrea" are 

 really the wings of a large species of Oecophylla described by 

 Cockerell as 0. megarche. For, on December 11th, 1915 

 (after the publication of my 'British Ants'), Professor 

 Cockerell published a paper on " British Fossil Insects," and 

 in it he described eight species of ants from the Oligocene of 

 the Isle of Wight, based on duplicate material rejected from 

 Brodie's Collection, and now preserved in the United States 

 National Museum as part of the Lacoe Collection. 



The locality in the Isle of Wight is Gurnet or Gurnard 

 Bay (both spellings appear in the maps), which lies a little to 

 the west of Cowes in the north of the island. 



This deposit has been placed both in the Bembridge series 

 = Middle Oligocene, and in the Osborne series, which is 

 Lower Oligocene, as also are the deposits of Aix and the 

 Baltic amber. Cockerell thinks, however, that the Gurnet 

 Bay fossils indicate a more decidedly temperate climate, and 

 consequently an age a little later than that of the Baltic 

 amber. He suggests that there was, perhaps, a mud-spring, 

 with heated waters, into which the insects fell, possibly over- 

 come by gaseous emanations. The waters were not themselves 

 poisonous, as fragments of rock carry also multitudes of a 

 species of Phyllopod Crustacean, the Branchipodites described 

 by Woodward (1879). Very many of the blocks I have 

 examined exhibit these crustaceans, and some are marked in 

 pencil " Branchiopode." Cockerell's contention with regard 

 to the mud-spring is supported by the fact that nearly all 

 the ants I have examined are winged, and were probably 

 overcome by the vapours during their marriage flights. 



