ANTHOPHILA. 133 



30. — Basal joint of four posterior tarsi Iohk. slender, subi-ylindrical, the tibia- 

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

 like or bituberculate i)rojec.tion beneath the insertion of the an- 

 tenna;: maxillary palj)! 4-jointed liitharKUii I>atr. 



Basal joint of four jwsterior tarsi more or less dilated, rarely subcylindrifal, 

 anterior tarsi % often broatlly dilated, rarely subcylindrical. their 

 coxae often arned with a spine ; tibiaj very rarely tuberculate, pul- 

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



raoKachile Latr. 

 31. — Antennie similar in both sexes, simple. 



Maxillary palpi 4 -Jointed ; abdomen globose or subglobose..OHniia Panz. 



Maxillary palpi .")-jointed; ab<lomen oblong Moiiiinietlia Cress. 



Antennie 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 apex, which is simple; 

 scape rather long and robust, most slender at base. 



Androniras 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 AlcidaineaCress. 



The genera characterized above may be arranged as in the list 

 given further on. . 



Both families need a thorough revision ; the Andrenidre are in 

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



Prof. Westwood divides the Andrenidse into two divisions, based 

 on the structure of the labium, viz. : the obtiisilingues, in which the 

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

 cordate and very short, containing the genera CoUetes 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 CoUetes have hairy, often fasciate bodies, and are 

 easily distinguished from all other bees by the second recurrent ner- 

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

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

 destitute of apparatus for collecting and carrying j)ollen ; in some of 

 the species of this genus the sca|)e or the basal joint of the % an- 

 tennfe is broadly dilated or Aleld-like. 



In Halictiis and Andrena the species are very numerous, some of 

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

 Unfortunately they have not been studied, and are therefore mostlv 

 unnamed. The species of both genera, like those of Pollster, etc., 



