Geological Society of London. 89 



optei'ons wings, thirty-three of which are referred to Ants of the 

 genera Myrmica, Formica, and Camponotus ; twenty -three examples 

 of NeurojDtera referred to Termes, Ferla, Lihellula, Agrion, Fliry- 

 ganea, and Hemerohius ; and twelve of Coleoptera, including species 

 of Hydrophilus, Bytiscus, Curculio, Anobium, Dorcus, and Staphy- 

 limis. There were also two Spiders. Several species of bivalved 

 Entomostraca have also been obtained from these deposits, and 

 identified by Prof. Eupert Jones. Of the Branchipod Crustacean 

 both sexes are fossilized and beautifully preserved, the males show- 

 ing their large clasping antennas, and the females their egg-pouches, 

 with large and very distinct disk-like bodies representing the com- 

 pressed eggs. Dr. F. Goldenberg notices a fossil from the Coal- 

 measures of Saarbriick which he regards as a Branchipod, and describes 

 and figures under the name of BrancMpusites (recte BrancMpoditef;) 

 antliracinus ; but this interpretation of it is at least doubtful. The 

 author names his species BrancJiipodites vectensis. The Isopods 

 accompanying this species are referred to the genus ArchcBoniscus, 

 M.-Edw., and one of them is identified with the Palceoniscus Bi-ong- 

 niarti of Milne-Edwards. The other is probably a new species, 

 perhaps nearly allied to the existing Sphoeroma serratwn. 



4. " The Chronological Value of the Pleistocene Deposits of 

 Devon." By W. A. E. Ussher, Esq., F.G.S., of H.M. Geological 

 Survey. 



In this paper the author endeavoured to work out the sequence of 

 events indicated by the Pleistocene deposits of Devonshire. He 

 believed that during late Tertiary times subsidence extended to the 

 south-western counties, and to this he ascribed with some doubt the 

 accumulation of a patch of gravel on the north summit of the Black 

 Downs and of part of the old bone-breccia of Kent's Cavern. In 

 the Glacial period, with the increase of cold, snow accumulated on 

 the high lands, with formation of glaciers, which descended and united 

 to form a great ice-field, planing the surface of a district composed 

 chiefly of Cretaceous and probably Tertiary strata. To this period 

 the author ascribed the formation of the clay with unworn fragments 

 of flint and chert, and doubtfully part of the clays of the Bovey 

 Valley, the clay of Petrockstow, and part of the bone-breccia and 

 the crystalline stalagmite of Kent's Cavern. The Postglacial pheno- 

 mena he referred to three subperiods, in the first of which, during a 

 gradual amelioration of the climate and disappearance of the ice, 

 large quantities of surface-water were set free, redistributing and 

 removing Tertiary outliers, partially destroying the old ice-beds, and 

 moraine rubbish, and sweeping Secondary deposits from Palceozoic 

 districts. The deposits then formed were supposed to be the old 

 gravel patches of Colford and Orleigh Court, the waterworn materials 

 on the Blackdowns and Haldon, the sands flanking the Bovey Valley, 

 and, with doubt, the redistributed Triassic pebble-beds of Straight- 

 way Hill, and part of the cave-earth of Kent's Cavern. The next 

 subperiod he regarded as one of great fluviatile action, the land being 

 higher than at present, though sinking, and the meteorological con- 

 ditions such as to greatly increase the volume of the rivers. The 



