BRITISH MUSEUM (NATURAL HISTORY). 103 



members of the Museum staff, has been issued in pamphlet 

 form, in nine parts, at 4(i. a part. 



(The Trustees propose also to issue these in book form 

 in one volume.) 



A new edition has been issued of the '' Guide to the Mineral 

 Gallery " (32 pp., 1 plan, 8vo. ; price \d.). 



Selections of the Natural History publications of the 

 Museum have been presented to several institutions and 

 individuals. 



The system of exchange of publications has been further 

 extended. 



The "under-mentioned works are in preparation : — 



A General Catalogue of the Books in the Library of the 

 Natural History Museum. 



Hand-list of Birds, Vol. III., by R. Bowdler Sharpe. 



Catalogue of Birds' Eggs, by E. W. Gates. 



Catalogue of Moths, Vol. III., by Sir G. F. Hampson. 



Monograph of Mosquitoes, by F. V. Theobald. 



Catalogue of Madreporarian Corals, Vol. IV., by H. M. 

 Bernard. 



Catalogue of the Welwitsch Collection of Tropical African 

 Plants, Vol. II., Part II. 



Illustrations of the Botany of Captain Cook's Voyage 

 Round the World in H.M.S. '' Endeavour " in 1768-71. By 

 Banks and Solander. Part II. 



Catalogue of Fossil Fishes, Part IV., by A. Smith Wood- 

 ward. 



Catalogue of Tertiara Mollusca, Part II., by G. F. Harris. 

 Catalogue of Cystidea, by F. A. Bather. 



Index Museum. 



In the department known as the Index Museum elaborate 

 models have have been made during the past year to illustrate 

 the minute structure of the gills of Lamelli branch Mollusca. 

 Much importance has recently been attached to the Molluscan 

 gill as an organ of taxonomic value, and the original obser- 

 vations which were a necessary antecedent to the preparation 

 of the models have brought to light many important facts 

 which must lead to a modification of the classification of the 

 Lamellabranchia hitherto adopted. 



Numerous larvae and embryos, in graduated series, have 

 been mounted to illustrate the successive changes undergone 



