PEEFACE. 



This Guide deals with the specimens which are exhibited in the 

 Southern half of the " Insect Gallery." The great group 

 Arthropoda, or animals with jointed legs and (usually) a hard 

 exoskeleton, are here considered, with the exception of the Insects, 

 which are described in a separate Guide. The present work is 

 thus concerned with the Crustacea, mainly aquatic in habit, and 

 represented by familiar animals such as Shrimps, Lobsters and 

 Crabs ; with the Arachnida, the Scorpions, Spiders, Ticks and 

 their allies ; with the Onychophora, constituted by the singular 

 animal known as Peripatus ; and with the so-called Myriopoda, 

 including the Millipedes and Centipedes. 



The section on the Crustacea is written by Dr. W. T. Caiman, 

 that on the Arachnida and Myriopoda by Mr. A. S. Hirst, and the 

 portions dealing respectively with the Onychophora and with the 

 Pentastomida (the latter regarded as degenerate Arachnida) by 

 Mr. F. Jeffrey Bell. 



Mr. Pk. I. Pocock, who was formerly in charge of the Arachnida 

 and Myriopoda, and whose responsibility then included the arrange- 

 ment of many of the specimens now exhibited, has been kind 

 enough to read the proof-sheets dealing with those groups. 



The thanks of the Museum are due to Messrs. A. and C. Black 

 for their permission to use certain blocks from Part vii (Dr. Caiman's 

 volume on Crustacea) of the " Treatise on Zoology," edited by 

 Sir Bay Lankester, k.c.b., f.r.s., who has also given his sanction 

 to their use in this Guide-Book. Figs. 10, 11, 13, 15, 18-22, 26, 

 27, 30 are derived from this source. 



SIDNEY F. HARMEE, 



Keeper of Zoology. 



British Museum (Natural History), 

 Cromwell Road, London, S.W. 



February, 1910. 



