240 LAWRENCE BRUNER. 



In describing bees of this group it would be well to employ such 

 characters as punctuation of face, thorax and abdomen ; the nature 

 of the triangle (inclosure) at the base of the metathorax — whether 

 bounded by a rim or by an impressed line; its surface, whether 

 rough or smooth ; shape and size of head and its attachments, as 

 antennae, tubercle at apex of clypeus, mandibles, etc. ; form of abdo- 

 men, depression of apical portion of segments; any special charac- 

 teristic of legs, as of tibiae and tarsi ; pubescence, length, abundance, 

 arrangement, color, etc. ; general color of wings, and indication of 

 variation of form and size in cells, nervures and stigma; abundance 

 and color of anal fimbria in the female ; also the general color of 

 the insect or of any portion of it. If all, or most, of these points 

 are kept in mind when a new form is characterized, the difficulty of 

 its recognition by others will be greatly lessened. It will also 

 enable the would-be tabulator to construct his key on characters 

 that are less artificial and therefore more constant than those em- 

 ployed here. 



While working over the described American forms it was found 

 that a few synonyms occur. In order to make the paper a trifle 

 more complete there are added below : 



Andrena bicolor (Arner. citations— not Fabr.) = carlini Ckll. 



" fimbriata Sm. = americana D. T. 



" flavoclypeata Sm. = bipunctata Cress. 



*' simidata Prov. = canadensis D. T. 



" clypeata Sm. = clypeolata D. T. 



" laticeps Prov. = Provancheri D. T. 



" serotina Rob. = Robertsonii D. T. 



" scutellaris Eob. = scutellata D. T. 



" hirticeps Rob. (not Sm.) = carlini Ckll. 



" Perezi Rob. = erythrogastra Ashm. 



A Preliminary Table for the Separation of the Species of Andrence 

 of America north of Mexico. 



Normally witb three submarginal cells in anterior wings — (Andrena, Tra- 

 chandrena, Opandrena, Ptilanerena, Pterandrena and Iome- 

 lissa 1. 



Normally with but two submarginal cells in anterior wings. ..(Parandrena) 229: 



1. Insect with the abdomen above more or less markedly rufous, ferruginous, 



orange or testaceous 2. 



Insect with the abdomen not at all rufous, ferruginous or orange, or if testa- 

 ceous, only slightly so at extreme apex of segmeuts 18. 



2. With the light color chiefly ferruginous or rufous 3. 



With the light color orange, yellowish or testaceous — basal, apical or both- .16. 



