THE MUSEUM 



NATURAL HISTORY. 



ZOOLOGY. 



Class V.— INSECTS (Insecta). 



In the following pages I intend to give, as far as space 

 and other circumstances admit, a general view of the 

 various orders of true Insects. By true is meant 

 Insects, as distinguished from Crustacea (sucli as 

 Lobsters, Shrimps, Crabs), Spiders (including Mites), 

 Centipedes (or Myriapoda), and such like, which are 

 all insects in the strict sense of the term ; that is, all 



Fig. 47. Fig. 48. 



t\ie of the Entomostracoiis Crustacea, 

 Bliowing very clearly anDUlose structure. 



Larva of a Beetle, 

 showing the an- 

 nulose structure. 



these classes have the body .composed of many seg- 

 ments or rings (annidi) — hence their general name of 

 Annulosa : while their various parts, such as the 

 antennae, organs of the mouth and head, tliorax and its 

 appendages, are all formed of various parts or joints, 

 as may be seen by looking at a Lobster, a Centipede, 

 or at any Beetle— oven the " black beetle " of the 

 kitchen, the Cockroach, which, however, we find be- 

 longs to a diflerent order to that containing the "gre.it 

 army" of Beetles — see figs. 47, 48, and 49. 



Jointed feet arc strikingly indicative of annulose 

 structure, and, hence, many naturalists call themCoNDY- 

 LOPA, or creatures with jointed feet. In dividing the 

 invettcbrated classes (those, namely, which have no 



real skeleton), we must hardly compare them with the 

 vertebrated animals. Insects are organized ou a totally 

 different plan. Most vertebrated animals have their 



Fig. 49. 



"'-fT^m 



Larva of Hydrous piccus. 



nervous system deranged, or destroyed by any injury 

 to the spine; but insects, or rather annulose animals 

 like insects — Spiders, Crabs, and Centipedes — are very 

 little, if at all, seriously injured in this way. Tho 

 nervous matter in Annulosa is collected in ganglia all 

 along the body, and I might enter on this ganglionic 



Fig. 50. 



Imago of large Water Beetle. 



structure were animal anatomy my object. Most of 

 tho Annulosa undergo great changes in their course of 



