424 BOARD OF AGRICULTURE. 



They are folded up lengthwise like a fan, and concealed beneath 

 the wing covers when at rest. A few of the species have the 

 wings or wing covers, one or both, much shortened or entirely 

 wanting. The mouth has jaws which move laterally against each 

 other, and they are used for biting or chewing. 



The Orthoptera have an incomplete transformation from the egg 

 to the adult state ; that is, they have no period of inactivity, but 

 closely resemble the adult from the time they leave the egg, except 

 in size and the absence of wings and wing covers. 



This order is represented in New England by the following 

 families : — 



Gryllid^, 

 locustid^e, 



ACRIDID^, 

 PHASMIDiE, 



Blattid^, 



whicli include the Crickets, 

 which include the Katydids, 

 which include the Grasshoppers, 

 which include the Walking-sticks, 

 which include the Cockroaches. 



EXTERNAL ANATOMY. 



To enable one to determine the species of the Orthoptera, it is 

 necessary to gain some acquaintance with the external parts and 

 their names. For this purpose we have introduced a brief descrip- 

 tion of the anatomy of a grasshopper, with illustrations, which will 

 serve for the Avhole order. 



An insect may be divided into three parts : Jiead, thorax and 

 abdomen. The thorax may be subdivided into prothorax, meso- 

 thorax and metatJiorax. See Fig. 1 . The head bears a pair of 

 jointetl antenna?, two large compound e^/es, three ocelU or simple 

 eyes (sometimes wanting) and the mouth parts. Fig. 1. The 

 mouth parts consist of an upper lip or labrnm, a broad flap which 

 closes over the mouth in front, a pair of jaws or mandibles, one on 

 each side, which move laterally, and by means of which they chew 

 their food. Behind the mandibles are a pair of smaller jaws, called 

 the maxUlce, which also move laterally, and to these are attached 

 a pair of small jointed appendages, called the maxillary palpi. 

 The maxillae are accessor}' jaws, used to hold and arrange the food 

 while it is being ground by t^ie mandibles. Behind the maxillte 

 is the lower lip or labium, which forms tlie lower side of the month, 

 and attached to this are a pair of jointed appendages, called the 

 labial palpi. See Fig. 2, where the mouth parts are shown sepa- 

 rated from each other. 



The prothorax has the fore legs attached to its under side, and 

 the part between the base of these legs is the prosternum, which is 

 sometimes a smooth piece extending from one leg to the otlier, and 



