84 NEW YoKK STATI-: MISKIM 



the dillereiit genera. Iii C h i r (Mi u in n s and allied genera 

 there is no trace of mandibles. In <'eratopogou the mouth 

 |;aris arc tilled for piercing. For homnlogjes of the mouth parts, 

 see Kellogg's papers in Psyche, IS!;!). The antennae or feelers are 

 \ariable in form and mini I ><T of joini s ; the ih-si visible joint (called 

 I'd joini b\ Mia II and Hammond P.Miih is usually enlarged, fol- 

 lowed b\ a se;-miil \\hidi is some) iim-s also somewhat enlarged, 

 these two Iteing called Hie scajie. These are always more or less 

 dill'erenl iated from the remainder, which constitute the Hagellum. 

 In Ihe male the joints of the llagellum are usually provided with 

 long hairs. The lirsi joim of Miall and Hammond i P.KiOj is the 

 e\t reiiieK short hidden one, which is sunk in t In- hi ad, and almost 

 entireh occupied by the muscles \\hirh move the antennae to and 

 fro. The next joint, the large one, exhibits a peculiar structure, 

 which is believed in ser\e lor I he percept i oll o f sound. (M. aud H. 

 P.MHI. and Mayer 1 ^7 1 . i The head is connected with the thorax 

 by a neck, whose cuticle is membranous. 



The thorax is composed of three parts, the prothorax, the ineso- 

 thorax and metathorax. The prothorax is t[iiite narrow, forming 

 a rounded collar back of the neck, within which are the mnsclis 

 of the foreleg. On ihe dorsal surface it appears as a narrowband 

 with a median incisure and suture. The liiimerus or humeral 

 callus belongs also to the proihorax according to Miall and Ham 

 mond iP.lllih. It is called (he paratreme by Lowne. The meso 

 thoi-ax is very lar^e; it is highly arched, and in some it projects 

 somewhat over the head. On its fore edge is the anterior thoracic 

 spiracle. The upper or dorsal surface of the mesothorax is often 

 called the mesoiiot um. and it has attached to it at its posterior 

 margin, and rut oil' from it by an impressed line, the scutellum, a 

 small, semioval body, which really belongs to the mesothorax (see 

 p].:n . tig. 16, C h a s m a t o n o t n s) . The wings are attached to 

 each side of and just below the scutellum. Behind and beneath the 

 scutellum is a smooth and rather prominent oval-arched portion, 

 the metanofum or upper portion of the metathorax (or post scutel- 

 lum of Miall and Hammond 1900) . Below and between the fore and 

 middle legs is a very prominent hemispherical part (especially in 

 Chironomus), the niesosternum. The sides of the body in 

 front of the wings are called the pleura, and the under surface of 



