and dissected in the dry specimen, or the head and mouth- 

 parts may be softened and bleached * before dissection. 



Remove the head with the beak from the dried specimen, 

 and examine the beak before dissection. The long, three- 

 jointed labium, forming all of the beak as seen superficially, 

 is specially chitinized (brown) near its distal end. The 

 distal joint is the longest, and its surface is sparsely covered 

 with fine, whitish hairs. The tip is rather blunt than acute. 

 A narrow channel, widest at its proximal end runs along the 

 upper face of the labium. In this channel, but concealed 

 by the approaching edges of it, lie the mandibles and max- 

 illae. A glimpse of the mandibles and maxillae just at the 

 base of the labium can often be had. Above the base of 

 the labium is the minute, acute-angled labruin lying just 

 over the entering mandibles and maxillae. 



With a dissecting needle carefully break away the head- 

 wall and muscle near the base of the beak, especially dorsad 

 and laterad. The bases of the mandibles and maxillce will 

 be discovered as small, strongly chitinized (brown), terminal 

 dilations of slender, chitin rods, which run forward into the 

 channel of the labium. Note the relative position of the 

 two rods with dilated bases on either side, and decide which 

 is mandible and which maxilla. (The rod lying slightly 

 dorsad and laterad of the other is the mandible ; the man- 

 dible is also thicker and larger than the maxilla. ) Trace 

 the slender chitin rods or stylets (the mandibles and max- 

 illae) into the channel of the labium. Here they are all 

 closely appressed, the two maxillae specially so, so that they 

 can be separated only with difficulty. 



In the softened and clarified specimen, the mandibles and 



* As in the bleaching of the locust and butterfly heads, the head with the beak of 

 the Cicada should be gently boiled in K O H until the parts are thoroughly soft and 

 clarified. If the clarifying proceeds too slowly, the head may be removed from the 

 K O H, washed in water, and placed in t,abbaraque's solution when the bleaching 

 will proceed rapidly. 



