the Apidse in the British 2Iuseum. 451 



15. (14) Hind calcar unarmed. 



16. (17) Scopa on outer side of tibia dark- 



haired ; tergites 1 and 2 basally 

 with griseous pubescence. Length 

 11 mm. (S. Africa.) rufomarginatus, Smith. 



17. (16) Tibial scopa pale-haired ; all the ter- 



gites with griseous pubescence. 



18. (21) Tegument of hind legs black. 



19. (20) The base of tergites 1-4 clothed with 



griseous pubescence ; a robust 



species. (Cape Colony.) eapicolus, Cam. 



20. (19) Tergites with only inconspicuous 



apical fasciae ; a slender species. 



Length 9 mm. (S. Africa.) communis, Smith. 



21. (18) Tegument of hind tarsi at least pale. 



22. (23) Tegument of hind legs entirely honey- [(Transvaal.) 



yellow latibatteata, Cam. 



23. (22) Hind tarsi honey-yellow riibricaudis, Cam, 



24. (11) Smaller species. 7 mm. and less. 



25. (26) Tegument of posterior tibiae ferru- 



ginous. Length 7 mm. (S. Africa.) ierminalis, Smith. 



26. (25) Tegument of posterior tibiae black. 



Length 6 mm. (Sierra Leone.) . . iridipennis, Smith. 



Halictus frontalis is the only male described by Smith. It is a larger 

 species than any of the females, with the exception of H. rufomarginatus. 



Halictus {Corynura) chilensis, Spin. 



Halictus chilensis, Spin,, Gay, Hist, fis. Chile, Zool. vi, 1851, p. 201, 



no. 1. $c?. 

 Corynura flavofasciata, Spin., Gay, I. c. p. 302. 6 • 

 Cacosoma marginatum, Smith, Descr. New Spec. Hymen, p. 41 (1879). 



J. 



Alfken has shown (Deut. ent. Zeit. 1913, p. 32,5) that 

 Corynura gayi, Spin., is t!ie male of H. rubellus, Halidaj. 

 Spinola seems to have forgotten that lie described the male 

 of H. chilensis when describing C. flavofasciata later on in 

 the same volume, for they are certainly co-specific. 



Megalopta, Smith (1853) . (Type M. hituherculata, Smith.) 



= Sphecodogastra, Ashm.(1899). Type : Parasphecodes texana (Cress.). 

 = Subgenus Megaloptidia, Ckll. (1900) . Type : M. contradicta, Ckll. S • 

 = S ubgenus ilfe^a/o/)<cZ/a, Schrottky (1906), Type: Halictus ochrias 



(Vach. 1904), 

 = Halicti megalopti, Vach, (1904). 



I cannot agree with those authors who sink this well- 

 defined group of Nearctic species to Halictus, a genus already 

 far too large for convenience. The size of the ocelli affords 

 an easily recognized and constant structural character. 



