8o NATURAL SCIENCE. Jan., 1893. 



The Walk of Arthropods. 



I WOULD like to supplement my paper on the " Walk of Arthropods " (Nat. Scl, 

 vol. i., p 676) by calling attention to Mr. Dixon's description of his researches, in 

 Nature, vol. xlvii., p. 56, in which some additional details are given, not included in 

 the paper reviewed by me. The spider (Tarentula) when running on water caused 

 depressions of the surface-film which were projected as dark shadows on the bottom 

 of the vessel. No shadows were cast by the foremost pair of legs, which proves that 

 the spider, like the insects, has a triangular base of support. The walk of centipedes 

 is also described ; the legs are said to move in alternate sets of three. 



In referring to investigators of the walk of insects, I regret that I omitted to 

 refer to Professors Miall and Denny, who in their book on the cockroach (p. 79) 

 give a short but excellent account of the locomotion of insects. 



Dublin, December, 1892. G. H. Carpenter. 



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The Publishers require a few copies of the October number {no. 8) of 

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Professor W. A. Herdman (University College, Liverpool) contemplates the 

 preparation of a Handbook to the British Marine Fauna, and desires to receive 

 suggestions from naturalists interested in the subject. He will also be glad to hear 

 from specialists who are willing to co-operate with him in the compilation. The 

 Professor proposes that the work should be a " pocket " or " seaside " handbook, 

 which could be used in much the same way as the botanists' " Field Flora." It 

 might comprise four to six small volumes, each dealing with one or two of the 

 large groups. There would be definitions— perhaps with occasional analytical tables 

 or keys— of orders, families, &c., down to and including genera. Abbreviated 

 descriptions of species would be added, with an indication of size, range, and 

 habitat. Simple figures would be given of all structural features of diagnostic 

 value in the various genera and species. 



