ANTHOPHILA. 133 



30. — Basal joint of four posterior tarsi long, slender, subcylindrical, the til>ia^ 

 usually tuberculate, pulvillus present in % ; face of 9 with a roof- 

 like or bituberculate projection beneath the insertion of the an- 

 tenna? : maxillary i)al]>i 4-jointed liitliui'^iiM T.atr. 



Basal joint of four posterior tarsi more or less dilated, rarely sul)i'yliudrical, 

 anterior tarsi % often broadly dilated, rarely subcylindrical, their 

 coxiE often armed with a spine; tibiae very rarely tuberculate, pul- 

 villus wanting in both sexes; maxillary palpi 2-jointed. 



Megacliile Latr. 

 31. — Anteniife similar in both sexes, simple. 



Maxillary palpi 4-jointed ; abdomen globose or subglobose..Osiiiia I'anz. 



Maxillary palpi 5-jointed; abdomen oblong Moilliilietlia Cress. 



Antennae dissimilar in the sexes, deformed in % , filiform and simple in 9 \ 

 maxillary palpi 4-jointed. 

 Flagellum % unequal, joints 2-5 dilated, joint 6 suddenly narrower and 

 the following joints gradually attenuated to a,\)ex, which is simple ; 

 scape rather long and robust, most slender at base. 



AiKlroiiieiis Cress. 



Flagellum % with compressed, submoniliform joints of nearly equal 



length, slightly attenuated toward tip, the apical joint suddenly 



constricted into a slender curved spine ; scape rather long and very 



robust AIci«lainea Cress, 



The genera characterized above may be arranged, as in the list 

 given further on. 



Both families need a thorough revision ; the Andrenidse are in 

 utter confusion, a large majority of the species being undescribed. 



Prof Westwood divides the Andrenida? into two divisions, based 

 on the structiu-e of the labium, viz. : the obtusUingue-s, in which the 

 central portion of the labium is obtuse, being either transverse or 

 cordate and very short, containing the genera Colletes and Prosopis ; 

 and the acutilingues, in which the central portion of the labium is 

 acute or lance-shaped, and containing the remaining genera of the 

 family. 



The species of Colletes have hairy, often fasciate bodies, and are 

 easily distinguished from all other bees by the second i-ecurrent ner- 

 vure being strongly curved outtvardlij towards the apex of the wing ; 

 while in Prosopis the body is coal-black and naked, and consequently 

 destitute of apparatus for collecting and carryiHig pollen ; in some of 

 the species of this genus the scape or the basal joint of the % an- 

 tennie is broadly dilated or shield-like. 



In Halidus and Amlrena the species are very numerous, some of 

 those of the former genus being among the smallest of our hees. 

 Unfortunately they have not been studied, and are therefore mostly 

 unnamed. The species of both genera, like those of Poliste,^, etc.. 



