T. D. A. and W. P. Cockerell on Bees. 47 
this group; but we find these unsatisfactory on account of 
the stress laid upon minor differences of venation, while 
certain radical differences in the mouth-parts of the genera 
are overlooked. This defect was perhaps unavoidable in a 
synopsis of the genera of the whole world, many of which 
could not at the time be examined for mouth-characters ; but 
it may be useful here to indicate the lines on which a_ better 
classification may be framed. 
Tribes. 
Paraglossee very long, hairy.......... Eucerini (Eucere, Patton, Bull. 
U.S. Geol. Sury. y. 471). 
Paraglosse not or hardly exceeding first 
jointioflabialipalpr: 2s wet cise s Anthophorini( Anthophore, Pat- 
ton, tom. cit. 475). 
Parazlossee very short; form robust, hind 
legs of 9 with a copious scopa: 
HEOLPOPICA CY POA» wits ees i070 ie" Centrint, 
CENTRINI. 
Maxallary: nalpi-4—|ointedis.. sfc siviests aps tele oyaitielee © Centris, Fabr. 
Maxillary palpi 6-jointed; paraglossz very short, 
broadcom sscale=|key Wirwectes ss 100 <.,0.016 acne aL 
1. First three joints of maxillary palpi twice as 
thick as, or at least noticeably thicker than, 
the last three; joint 4 about as long as 3... Evomalopsis, Spin. 
All joints of maxillary palpi of about equal 
thickness and slender ; joint 4 longer than 3; 
1 not over half length of 4; clypeus yellow 
INGA CY 5, suarsta cease Meas tha es eae Anthophorula, Ckll. 
(Diadasiella, Ashm.), 
We find also certain differences between species of these 
genera, which may be found to indicate subgenera. 
CENTRIS. 
Last joint of maxillary palpi short, not half 
length of penultimate joint; penulti- 
mate (third) joint less than half length 
ousecond’?) flight slow 2s. %.<..s.ass C. pallida, Fox. 
Last joint of maxillary palpi longer, over 
half length of penultimate joint; penul- 
timate two thirds length of second: 
HA OIDRVOLY ATA DIGS oy. sf. v.c-n1s hatstese vaaeer C. rhodopus, Cll. ; C. Hoff- 
manseggi@, Ckll, 
The measurements of the last three joints of the maxillary 
palpi here given are in w :— 
C. pallida . . . (2) 430, (3) 189, (4) 84. 
C. rhodopus. . . (2) 300, (3) 235, (4) 188. 
The C. pallida studied is a cotype kindly sent by Mr, Fox. 
