— 24 — 



the claws ; this is often referred to in descriptive works as 

 the pulvillus. 



NOTE. — In the membrane connecting the coxa with the thorax, just 

 cephalad of the coxa, is a sclerite ; this I believe to be the trochantin. 

 The trochantin is a sclerite which is considered to be an appendage of 

 the coxa ; and its normal position is between the coxa and the epi- 

 sternum. 



Make a drawing of one of the cephalic legs. 



The same parts may be traced on each of the other legs. 



Wings. — The wings are plate-like or membraneous ex- 

 pansions of the body-wall. Each wing is traversed by many 

 linear thickened portions ; these are termed veins, or nerves. 

 The principal veins extend proximo-distad. These are 

 joined together by many smaller veins or veinlets. The thin 

 parts circumscribed by the veins and veinlets are called cells. 



The two pairs of wings of a locust differ remarkably in 

 form and texture. 



Mesothoracic Wings ( Tegmina) . — The mesothoracic wings 

 are long, narrow, and of a parchment-like texture. They 

 are termed tegmina. 



Metathoracic Wings. — The metathoracic wings are much 

 larger and of more delicate texture than the first pair of 

 wings. When not in use they are folded in plaits like a fan 

 and concealed by the tegmina. Some writers who designate 

 the mesothoracic wings as tegmina or wing-covers, describe 

 the metathoracic wings simply as the wings. 



Make diagrams showing the outline of one of the wings of 

 each pair. Do not attempt to represent the veins and vein- 

 lets ; a special study of wing-venation will be made later in 

 the course. 



parts of the; abdomen. 



Number ot segments. — There is a difference of opinion 

 as to the number of segments in the body of a locust. The 

 difficulty arises from the complexity of the caudal end of 



