GUIDE 



TO THE 



CRUSTACEA, AEACHNIDA, 

 ONYCHOPHOliA AND MYiUOPODA. 



The specimens exhibited in the " Insect " gallery belong to the 

 comprehensive group Arthropoda, of which the animals usually 

 known as Insects form only one of the divisions. 



The Arthropoda may be defined as animals in which the body 

 is more or less distinctly segmented, generally with a firm external 

 skeleton, and with jointed limbs, some of which are modified to 

 serve as jaws. 



The group is divided, according to the system of classification 

 followed in arranging the gallery, into six Classes : — 



Class 1. — Crustacea (Crabs, Lol;)sters, etc.). 



2.— Trilobita. 



3. — Arachnida (Spiders, Scorpions, etc., with 



Appendix, Pentastomida). 



4. — Onychophora (Peripatus). 



5. — Diplopoda (Millipedes). 



6. — Pauropoda. I T>,r ^ . 



^ \ Myriopoda. 



7. — Symphyla. 



8. — Chilopoda (Centipedes). 



9. — Insecta (Moths, Fhes, Beetles, etc.). 



The Insecta are arranged in the northern half of the Gallery, 

 and are described in a separate Guide. The remaining classes 

 occupy the southern half of the Gallery, and are dealt with here 

 in the order j^iven alcove. 



