1895.] NATURAL SCIENCES OF PHILADELPHIA. 365 



3. First joint of medial tarsi curved 4 



First joint of medial tarsi not curved 12 



4. .Medial femora serrate or carinate beneath, or broadly emarginate 5 

 Medial femora smooth beneath 11 



5. Eighth ventral, with a discal spine 6 



Eighth ventral, without a discal spine 8 



6. Apical joint of fore tarsi greatly enlarged ; fore femora flattened 



(second ventral segment unarmed) speciosa. 



Apical joint of fore tarsi not enlarged ; fore femora not flat- 

 tened 7 



7. " Second ventral segment flat and unarmed ; pulvilli scarcely dis- 



cernible." serrata. 



Second ventral segment with two approximate tubercles near 

 posterior margin ; pulvilli distinct < marginata.* 



8. Second ventral segment tuberculate 9 



Secoud ventral flat, not tuberculate (mesopleura? and middle-seg- 

 ment not at all yellow) plana. 



9. Intermediate and posterior femora broadly emarginate or strongly 



incurved (second ventral segment bituberculate ; pulvilli dis- 

 tinct) femorata. 



Intermediate and hind femorara not emarginate or incurved . 10 



10. Second ventral segment with two small tubercles ; femora above 



black at base only ; pulvilli small, indistinct .... pulchella. 



Second ventral segment with a single large tubercle; femora above 



with a black stripe ; pulvilli distinct tuberculata. 



11. Second ventral segment flat, not tuberculate ; antenna? as usual, 



not long. Length, 12-13 mm pictifrons. 



Second ventral segment with two large acute tubercles ; antenna? 

 unusually long and slender. Length 18 mm. . . . tenuicornis. 



12. Fore legs with the tarsal comb but feebly developed ; second ven- 



tal segment bituberculate 13 



Fore legs with an extremely long and distinct tarsal comb ; second 

 ventral segment flat, not tuberculate ; front narrow . . . pulla. 



13. Head and thorax rather densely clothed with long hair ; dorsulum 



with two central yellow spots vttlosa. 



Head and thorax not densely pubescent, sparsely so ; dorsulum 

 without central yellow spots usitata. 



1. Monedula signata Linne. 



Vespa signata'Linne, Systema Nat., Ed. X, Vol. I, p. 574. 

 Bembex signata Fabricius, Syst. Ent., p. 3(31. 

 Apis vespiformis De Geer, Meinoires, III, p. 570, PL 28. f. 3. 

 Bembex vespiformis Olivier, Encycl. Meth., IV, p. 290, PI. 106. f. 18. 

 Vespa diadema Christ. Naturg. d. Ins., p. 223, PI. 19, f. 7. 

 Jfouedu/a signata Lepeletier de St. Fargeau, Hym. Ill, p. 283. 



This is the commonest tropical species and is recorded from Mex- 



*M. mamillata Handl., which I have not seen, may be identical with emar- 

 ginata. 



