10 GEO. H. HORN, M. D. 



Tlie different genera present so many modifications of structure, 

 while preserving the same general type, that it is unnecessary here 

 to deal more fully with them as they more properly belong to the 

 generic descriptions. 



This tribe is the equivalent of the Eucnemitea propres as defined by 

 de Bonvouloir, and contains eighty-seven genera, twenty of which 

 are represented in our fauna. Having less material to deal with 

 than he, I have been enabled to modify the table of genera in such 

 a way as to use characters more readily seen and to avoid exceptional 

 cases. For the latter i-eason I have been compelled to avoid the use 

 of the coxal plates near the beginning of the table, inasmuch as two 

 species of Microrhagus have parallel coxal plates and might be sup- 

 posed to belong to Hylochares. 



The characters used in the following table seem not to require 

 special explanation, in case of doubt reference should be made to the 

 genera themselves. 



Thorax with anteuual grooves usually sharply limited, close to the lateral 



margin 2. 



Thorax without marginal antennul grooves 8. 



2. — Tarsi with joints 2-4 lobed beneath Deiidrocliaris. 



Tarsi with the fourth joint, at most, slightly lobed 3. 



3. — Pi-osternal sutures arcuate ^itetlioii. 



Prosternal sutures straight 4. 



4. — Antennal groove continuing directly from the thorax to the head 5. 



Antennal groove more or less interrupted or narrowed by the eyes 7. 



5. — Metasternum with a fine groove, limited by finely elevated lines, pro- 

 longed backward from the outer side of the middle coxae ; propleural 



triangle small Eiieiieiiiis. 



Metasternum without groove 6. 



6. — Antennal groove of thorax wide, at least equal to half the propleural 



triaiagle, usually wider behind Deltoiuotopu^^. 



Antennal groove narrow, not more than a fourth as wide as the propleu- 

 ral triangle, not wider behind Droin»M>lii!$. 



7. — Antennge slender, fourth joint of tarsi excavate-emarginate and slightly 



lobed beneath Fornax. 



Antennse short, clavate, fourth joint of tarsi simple ....Pliaoii<»('ei*u»<«. 



8. — Lateral margin of thorax formed by two finely elevated lines, the one 



starting from the anterior margin and prolonged backward, the other 



from the hind angles becoming inferior ; antennal grooves juxta-su- 



tural 9. 



Lateral margin of thorax single, sometimes nearly entirely obliterated; 

 under side of prothorax without antennal grooves, at most a faint lon- 

 gitudinal depression in the triangle 10. 



9. — Juxta-sutural groove very short, merely slightly indicated in front. 



Adelotliyretis. 



