14 BRITISH MUSEUM (NATURAL HISTORY) 



rearranged and a new guide-book prepared in explanation of this 

 collection. The most prominent addition to the department during 

 the year was a mass of silica-glass, of unknown origin, found on the 

 surface of the Libyan Desert. 



Special exhibits of plants collected by Cai^tain Kingdon-Ward in 

 Tibet and Burma, X-ray photographs of flowers and fruits, lent by 

 Messrs. Ilford, a further selection of clay models of flowering plants, 

 lent by Miss G. Huxham, and a model showing the effect of heath 

 fires were set out in the Department of Botany. An exhibition of 

 fresh specimens of fungi was continued for several weeks in the autumn, 

 and at the end of the year an exhibit of volumes from the Sloane 

 herbarium was set up in connexion with the exhibit in the Central Hall. 



Study Collections. 



The usual work of naming, labelling, registering, and incorporating 

 accessions continued in all departments. As in previous years, the 

 Trustees are much indebted to numerous workers who gave their 

 services voluntarily, many of whom worked continuously throughout 

 the year. Research workers were given access to the collections in all 

 departments and were assisted in their investigations. 



The rearrangement of the collection of ungulate skins was continued. 

 The entire collection of skulls and skeletons of the smaller Cetacea was 

 removed to the basement of the Whale Hall, and the ungulate and 

 human collections in the Osteological Room were rearranged in the 

 space thus set free. Various improvements were effected in the 

 arrangement of the bird collections, especially in the reconstructed 

 cabinets for holding the skins of the larger birds. The collection of 

 frogs was largely rearranged to meet modern views of classification. 

 In the Arachnida section a very large number of microscopical pre- 

 parations of Acari were remounted. 



In the study collections of the Department of Entomology the 

 expansion consequent upon the incorporation of accessions and detailed 

 revision was continuous. In the Lepidoptera the greatest advance was 

 made in the Hesperiidae, the Lymantriidae and the Microlepidoptera ; 

 in Diptera the nematocerous families and the Dolichopodidae and 

 Syrphidae received most attention ; in Hymenoptera considerable 

 progress was made with the sawfly and ant collections, and it at last 

 became possible to make a serious attack upon the hitherto much 

 neglected parasitic groups. Work was continued upon the Coleoptera 

 along general lines and in the neuropterous groups the Trichoptera 

 collections were very greatly improved. In Orthoptera it is not 

 possible to record any especial progress owing to lack of staff, and in 

 the Hemiptera most advance was made in the Membracidae, Aphididae 

 and Coccidae, all groups of considerable economic importance. 



In the Department of Geology work was done on Miocene, Pliocene 

 and Pleistocene mammals from France ; Amphibia from Nova Scotia ; 

 Eocene and Oligocene Gastropoda and Lamellibranchia ; and Cretaceous 

 Lamellibranchia. The Tertiary Decapod Crustacea were all relabelled 

 and much reregistering was done in connexion with the forthcoming 

 Catalogue of Cirripedia, Vol. II. The Geological Society's collection 

 of foreign Brachiopoda was labelled and incorporated in the general 

 collection. 140 thin sections of various fossils were made for the 

 purpose of study. 



In the Department of Mineralogy a special study was made of the 



