STELIS. 263 



over the post-scutellum and metathorax, mucronatecl 

 laterally ; metathorax abruptly truncated ; wings with 

 two submarginal cells, and a third very slightly com- 

 menced, the two subequal, the second being the largest 

 and receiving the first submarginal cell near its com- 

 mencement and the second at the inosculation of the 

 terminal transverso- cubital nervure; legs short, mode- 

 rately stout, the tibiae very slightly setose externally; 

 claws short, bifid, the internal tooth near the external. 

 ABDOMEN oblong, truncated at its base, very convex above 

 and flat beneath, deflexed towards its extremity, and the 

 terminal segment almost rounded, being very slightly 

 produced in the centre and margined. 



The MALE scarcely differs, excepting in the usual male 

 characteristics, and by the apical segment being obso- 

 letely tridentate. 



NATIVE SPECIES. 



1. aterrima, Panzer, $ ? . 4-4J lines. 

 punctulatissima, Kirby, 



2. phceoptera, Kirby, $ $ . 4-4J lines. (Plate XT. 



% 3 rf ? .) 



3. octomaculata, Smith, ? . 3 lines. 



GENERAL OBSERVATIONS. 



The name of this genus may be derived from crreXt?, 

 a sort of parasitical plant, perhaps mistletoe, if we could 

 be sure that Panzer imposed it after being aware of the 

 parasitical nature of these bees. It is true his book (the 

 1 Revision ') was published in 1805, and Kirby, who 

 first intimated a suspicion of such cuckoo-like habits in 

 some of the bees, published his in 1802; therefore it 

 might have been given in allusion to that peculiarity of 



