THE IIELAXDRYID BARK BEETLES. 12S7 



Horn, in his latist paper above cited, divides the family into ten 

 tribes. Of these representatives of seven have been taken in In- 

 diana, while those of two others probably occur. 



KEY TO INDIANA TEIEES OF iIELANDBYID.5;. 



a. Xext to last joint of all the tarsi simple; front tarsi of males not di- 

 lated ; thorax as wide at base as elytra. 

 h. AnteuiuL- with last three or fonr joints suddenly larger, forming a 

 1 X se. strongly developed club ; length less than 6.5 mm. 



Tribe I. Tetratomixi. p. 12s7. 

 66. Anteume gradually thicker or filiform. 



c. Front eoxal cavities with an outer fissure or cleft. 

 0. Third joint of anteunse as long as fourth and fifth together; form 

 broadly oval. Tribe II. Pexthixi. p. lliSO. 



dd. Third joint of anteiuiw imi much longer than fourth; form elon- 

 gate. 

 e. Front cox;e not prominent, rather widely separated; spei-ies 

 strongly resembling iliJaiwtus; length 10-11 mm. 



Tribe III. SyxciiKiJiM, p. Vl'M. 



ce. Front coxse moderately prominent and nearly ciitiguous; color 



piceous ; length 15-S..") mm. Trilte IV. Mai.! (>:)BY1xi, p. 1201. 



cc. Front eoxal cavities without fissure; form oval c.r oblong, convex. 



Tribe V. Okchesiixi, p. 1291. 

 aa. Next to last joint of front and middle tarsi excavate and emarginate, 

 more or less lobed beneath; front tarsi of males dilated. 

 /. Tarsal claws simple or ^ery slightly broader at base; thorax as wide 

 at base as elytra. 

 (f. Head not constricted behind. Tribe VI. JIelaxdsyixi. p. 120.j. 



(,</. Head suddenly constricted behind the eyes; small species, not over 

 5 mm. in length. Tribe VII. Si raptiixi, p. linio. 



ff. Tarsal claws with a broad tooth or lobe at base. 



;(. Jliddle eoxal cavities open on the outer side; head not prolonged; 

 thorax as wide at base as elytra, its side margins entire, acute. 



Tribe VIII. Xothixi, v. 1.301. 



hh. Middle coxal cavities enclosed by the sterna; head more or less 



prolonged in a beak ; thorax not as wide at base as elytra, its 



margin evident at l>ase only. Trilie IX. Mycteeixi, ]i. 1.'',02. 



Tribe I. TETRATOMINI. 



This tribe comprises small, oval convex forms living in fungi 

 and havinsr the last three or four joints of antennae much enlarged, 

 nearlv equal in size and forming a loose club; tibial spurs small; 

 next to last tarsal joint not lobed, claws simple, coxae all separated 

 bv their respective- sterna. Casey, locality cited, has divided the 

 tribe into five genera, three of which are represented in the State, 

 while a sinfcle species of another may occur. 



