No. 34-] HEMIPTERA OF CONNECTICUT I LYGAEIDAE. 723 



Tribe MYODOCHINI. 



Key to Genera. 



1. Head exserted or not, but never drawn out into a long cylindrical 



neck. Collar more rarely absent 2 



Head very much exserted, drawn out into a long cylindrical neck 

 at base; longer than pronotum. Two lobes of pronotum sub- 

 equal. Body narrow elongate. Hind tibia furnished with long, 

 setose hairs. Basal segment of hind tarsus about three times as 

 long as second and third together. Macropterous forms only . . . 



Myodochus, p. 724 



2. Pronotum commonly constricted at middle or a little behind middle ; 



anterior lobe black, in all macropterous forms and in most 

 brachypterous forms never or scarcely ever more than twice as 

 long as posterior lobe ; if more than doubly longer then the head 

 is not exserted (as in brachypterous forms of some Ptochiomera) 3 

 Anterior lobe of pronotum three or four times as long as posterior 

 lobe, with transverse constriction between lobes commonly shallow 

 or ill-defined. Head distinctly exserted. Fore tibia of males 

 provided with a submedian tooth. Antennae elongate. Basal 

 segment of posterior tarsus two or three times as long as second 

 and third segments together. Brachypterous forms common 9 



3. Head more or less distinctly exserted. Pronotum with a con- 



stricted ring-like collar. Body more or less elongate 4 



Head not at all or scarcely exserted, commonly immersed to eyes. 

 Pronotum without a constricted ring-like collar, at most with 

 anterior margin depressed or furnished with a series of punctures ; 

 strongly constricted to form two lobes, both of which are punc- 

 tate, the disk of the anterior one sometimes more sparingly so. 

 Clavus with three rows of punctures. Posterior tarsus with 

 basal segment subequal to second and third together 8 



4. Head commonly strongly contracted back of eyes ; postocular space 



commonly subequal to or sometimes shorter than space between 



base of antenna and eye 5 



Head strongly exserted, forming a short neck at base; postocular 

 space about four times as long as space between base of antenna 

 and eye. Eyes placed about midway on head. Hind tibia pro- 

 vided with fine rigid bristles. Basal segment of posterior tarsus 

 about as long as second and third together. Macropterous and 

 brachypterous forms Heraeus, p. 725 



5. Second and third ventral abdominal segments not furnished with 



finely strigose lunate vittae 6 



Second and third ventral abdominal segments furnished on each 

 side with a finely strigose, lunate vitta Ligyrocoris, p. 725 



6. Two lobes of pronotum commonly separated by a more shallow 



obtuse constriction. First segment of rostrum commonly reach- 

 ing base of head 7 



Two lobes of pronotum separated by a deep, clean cut, transverse 

 constriction. First segment of rostrum not reaching base of head. 



Hind tibia most commonly furnished with short bristles 



Orthaea, p. 727 



7. Posterior tarsus with basal segment fully three times as long as 



second and third together. Hind tibia provided with long rigid 

 bristles only. Antennae legs and body nearly nude. Form of 

 body narrow-elongate, with longer legs. Scutellum carinate 



throughout Zeridoneus, p. 727 



Posterior tarsus with basal segment not more than twice as long 

 as second and third together. Body, legs and antennae furnished 



