126 ACCOUNTS, ETC., OF THE BRITISH MUSEUM. 



VI. — Economic Zoology. 



Tlie main work of the Department, tKe determination, con- 

 servation and arrangement of collections of animals, is the 

 foundation of economic research, which depends on a knowledge 

 of species and their distribution. This is more particularly- 

 evident in the case of groups such as the Parasitic Acari and 

 Parasitic Worms, each of which has occupied the full time of 

 an assistant. Museum work on Fishes arid other marine animals 

 is closely related to fishery development, and collections dealt 

 with during the year include one from a new British fishing 

 ground, received from the Ministry of Agriculture and Fisheries, 

 and others sent for determination by the fishery authorities in 

 Natal. 



Members of the staff have answered many enquiries on 

 economic subjects and have determined a number of specimens 

 sent in connection with economic work ; the following are 

 examples : — 



I. Mammalia. 



Bats which attacked a grove of Araucaria in the Gold Coast 

 Colony, stripping the trees of their bark, were determined as 

 the common fruit Bat, Eidolon helvum. 



Information was given as to the possibility of establishing 

 trade in the skins of West African Otters. 



Rats and Mice, in relation to the public health and general 

 economics, have again received much attention. Information 

 and advice have been given in response to requests received from 

 many public bodies and private individuals. 



II. Mollusca. 



A large number of Shipworms and other marine Mollusca 

 destructive to timber have been determined for a Committee of 

 the Institution of Civil Engineers which is conducting an inquiry 

 into this subject, and a report on a part of the collection has 

 been published. 



Advice was given with regard to water-pipes choked by the 

 growth of Mussels. 



The operculum of a Gastropod is the source of a native dye 

 extensively used and traded m E. Africa; the species was deter- 

 mined. 



Advice has been given in connection with work on tropical 

 diseases in the West Indies. 



Several determinations of Molluscs injurious to crops, trees, 

 etc., have been made for the Imperial Bureau of Entomology. 



Applications for specimens of the Gastropods concerned in 

 the transmission of Schistosomiasis (= Bilharziasis) having been 

 received, steps were taken to obtain a supply, and a new form, 

 acting as intermediate host, was discovered. 



III. Arachnida. 



Mites {Carpoglyphus anonymus) infesting jam; the species 

 was determined and advice was given. 



Furniture Mites [Glycyphagus domesticus) infesting houses; 

 advice and information were given. 



