the A[)itUi.' in the British Museum. 151 



I'"). (14) Hind cnlcar unarmed. 



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



liaired ; ter^'ites 1 and 2 I)a5<aily 



with griseoiis ])ubescence. Lenj,'!!! 



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



17. (10) Tibial 3copa pale-haired ; all tiie ter- 



^ates with griseous pubescence. 

 1"^. (lM) Tegument of hind legs black, 

 lit. (:.'U) The base of tergites 1-4 clothed with 



griseous pubescence ; a robust 



species. (Cape Colon}.) capicolm, Cam. 



20. (in) Tergites with only inconspicuous 



apical fascia3 ; 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 liitibnlteata, Cam. 



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



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



25. (26) Tegument of posterior tibiae ferru- 



ginous. Length 7 mm. (S.Africa.) <crHima/t«, Smith. 

 2G. (25) Tegument of posterior tibiiB black. 



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



6 6. 



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

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



Halictus {Corynurd) chilensis, Spin. 



Halictus ckileJisis, Spin., Gay, Hist. lis. Chile, Zool. vi. 1851, p. 201. 



no. I. 2 6. 

 Corijnurajlavofasciata, Spin., Gay, /. c. p. 302. 6 • 

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



6. 



Alfken has shown (Deut. ent. Zeit. 1913, p. 325) that 

 Corynura gnyi. Spin., is the male of //. rubellus, lialidaj. 

 Spinola seems to have forgotten that he described the male 

 oi M. chilensis when describing C. jlavofasciata later ou in 

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



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



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

 = Subgenus Megaloptidia, Ckll. (1900). Type : M. contradicta, CkU. cT . 

 = iiuhpeau9 Megaloptel/a, Schrottky (190G). Type: Halictus ochrias 



(Vach. 1904). 

 = Hulicti megalopti, Vach. (1904). 



I cannot agree with those authors who sink tliis well- 

 defined group ot Nearctic species to Halictus, a genus already 

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

 an easily recognized and constant structural chaiacter. 



