CYDNIDAE OF THE WESTERN HEMISPHERE — FROESCHNER 381 



Anterior part of osteolar peritreme without enlarged, differentiated apical 

 structure, sometimes with a small, subapical, posterior hooklike or flaplike 

 projection (figs. 102-112) 8 



2. Osteolar peritreme with apical process elongate, transverse length three or 



more times width (figs. 91-94) 3 



Osteolar peritreme with apical process short, transverse length not more than 

 two times width 4 



3. Osteolar peritreme an elevated, troughlike structure extending almost to 



lateral margin of segment where it forms a recurved, polished lobe (fig. 



91) Macroporus Uhler (p. 394) 



Osteolar peritreme a transverse polished band, neither elevated, troughlike 

 nor recurved apically (figs. 92-94) Rhytidoporus Uhler (p. 382) 



4. Membrane occupying half of hemelytral length (figs. 4, 15) 5 



Membrane not more than two-fifths of hemelytral length 6 



5. Terminal osteolar process large, elongate-oval, with one to three longitudinal 



rugae discally (fig. 89) Cydnus Fabricius (p. 406) 



Terminal process of peritreme small, not elongate (figs. 100, 101). 



Ectinopus Dallas (p. 410) 



6. Metapleural evaporatorium very limited, just outlining peritreme, not 



approaching metapleural lamella posteriorly (fig. 90). 



Microporus Uhler (p. 397) 



Metapleural evaporatorium more extensive, occupying more than half of 



sclerite and nearly or quite reaching base of metapleural lamella posteriorly 



(figs. 91-103) 7 



7. Terminal process of peritreme scoop-shaped or auricular, with osteole con- 



spicuously visible ventrally at its base (fig. 95). Onalips Signoret (p. 415) 



Terminal process of peritreme flat, simply expanded posteriorly as a more or 



less polished lobe, osteole opening po.steriorly, not conspicuous ventrally 



(figs. 96, 97) Melanaethus Uhler (p. 421) 



8. Pronotum anteriorly with deep, sharply impressed line paralleling anterior 



margin from side to side (this line usually impunctate). 



Pangaeus Stai (p. 455) 



Pronotum anteriorly without this impressed line, although often with a row 

 of punctures in the same area (rarely with partial, vague line laterally) . 9 

 9 Posterior tibia conspicuously compressed, anterior and posterior faces 

 glabrous, not spined; spines of postero ventral margin conspicuously 

 longer, thinner and more tapering than those of dorsal margin (figs. 141, 

 142) .10 



Posterior tibia not or only weakly compressed; dorsal and ventral spines 

 about equally developed H 



10. Labial II with large, semicircular, foliaceous lobe, this often hidden between 



anterior coxae (fig. 36) ... . Prolobodes Amyot and Serville (p. 508) 



Labial II somewhat compressed, but without large, foliaceous lobe (fig. 34). 



Cyrtomenus Amyot and Serville (p. 514j 



11. Head with a complete row (extending from eye to apex of jugum) of coarse, 



more or less contiguous punctures giving rise to numerous long hairs and 

 usually also to a row of pegs (figs. 54, 55). 



Tominotus Mulsant and Rey (p. 539) 

 Head without a complete row (absent or extending not more than three- 

 fourths of way to apical angle of jugum) of coarse setigerous puncture; 

 pegs never present (figs. 41-45) Dallasiellus Berg (p. 570) 



