rj 



OF THE TABAXIDJi: OF THE UNITED STATES. 371 



_ f Both basnl cells nre infiiscated on tlieir proxiniiil half 4. 



" I St'conil basal cell hyaline ; face fenuginous in the middle 7. niger 3Iacq. 



jAbdonicn marked with more or less yellow on the sides 5. 



I Abdomen altogether black 6. 



r Abdominal segments with narrow gray borders posteriorly; the yellow spots on the sides of the first 

 two abdominal segments small 6. sordidus n. sp. 



Ab loininal segments without any gray hind borders; the yellow spots on the sides of the abdnmen 



usually large 2. excitans Walk. 



r Thorax with a conspicuous tuft of yellowish-ferruginous hairs on each side, in front of the 



6. -\ wings 5. celer n. sp. 



[Tliorax with pale yellowish hairs on the sides 7. 



fFifth posterior cell filled out with brown at the proximal end; thorax with two rather distinct whitisli 

 lines anteriorly 3. mitis n. sp. 



Fifth postei'ior cell with a small hyaline spot at the proximal end; no distinct while lines on the 



I thorax 4. fugax n. sp. 



r Whole body brownish-yellow ; abdomen with a pale-brownish design .... 5. flavidus Wied. 

 1 Body more or less black (or at least with black longitudinal stripes on the abdomen) .... 9. 



Both basal cells hyaline ^ 10. 



First basal cell altogether, or to a considerable extent, infuscated 17. 



f Tlie ajiical spot consists of a narrow- brown border along the costa, between the crossband and the 

 I apex; (distal half of the first subraarginal cell, except at its extreme end, hyaline) . . . .11. 

 I Tlie a[)ical spot is broail, and fills out a considerable portion of tlie distal half of the fii'st sulmiar- 

 . ginal cell 13. 



f Crossband in the usual shape, not attenuated posteriory 12. 

 Crossband attenuated posteriorly, the brown occupying but a small portion of the discal and fourth 

 posterior cells 10. delicatulus n. sp. 



fA black triangle encroaches upon the yellow on each .side of the A'S'i'iped l)lack s]iot on the second 

 abdominal segment 8. aestuans v. d. "Wulp. 

 N"o black tri.-mgles on the sides of the A-shaped black spot on the second segment. 9. callidus n. sp. 

 (Tiie hj'aline triangle, between the apical spot and the crossband, stops short at the second longitudinal 

 vein 14. 

 The hyaline triangle, etc., is prolonged beyond the second longitudinal vein, towards the co.sta . . 15. 

 r Second and thinl abdominal segments black, with yellow hind margins, expanded into tiiangles in the 



I middle; frontal callosity reddish 11. pudicus n. sp. 



"'l Second and third abdominal segments yellow, with four broad longitudinal black lines, which are often 

 [ broailer than the intervening yellow spaces; frontal callosity black . . . 12. montanus n. sp. 

 ■Abdomen dark brown, or black above, with a yellow longitudinal stripe, attenu.ated posteriorly, and 



two shorter and narrower stripes on each side 23. obsoletus Wied. 



I Abdomen yellow above, with two small, converging black spots on the second segment ; segments 

 [. three and four black and yellow 16. 



{The crossband reaches the ](Osterior maigin 22. fallax n. sp. 

 The crossband does not quite reach the posterior margin, the fourth posterior cell not being quite filled 

 out with brown 21. hilai'is n. sp. 



iThe species referred to here have, in pome instances, an C. momanua, wUicli has the largest inftiseation of the first 



inconsiderable infuscation at the pro.xiraal end of the first basal cell, among all the species referred to Xo. 10. 

 basal cell, while the species referred to No. 17 have this cell C./rir/idus, which has the smallest infuscation among the 



infuscated far beyond the midille. . Between these alterna- species referred to No. 1 7. 

 tives, a doubt may arise in the following cases only. 



