Messrs. T. D. A. Cockerell and VV. Porter on Bees. 405 



palpi are based on broken specimens, as we have found that 

 the loss of one or two joints of a palpus is often very difficult 

 to detect without the use of a high power of the compound 

 microscope. 



The species with 5-jointed maxillary palpi are very diverse 

 among themselves, as follows : — 



(1) Joint 4 about equal to 5 and not greatly 



shorter than 3 ; fourth joint of labial palpus 

 narrow and cylindrical ; insect black ; apex 

 of abdomen ( c3" ) truncate cucurbitina, Rossi. 



(2) Joint 4 conspicuously shorter than 3 or 5 [(Europe.) 

 (rt) Joint 5 very narrow, only about half width 



of 3 ; fourth joint of labial palpus broadly 

 truncate at end ; insect with the thorax 



green, abdomen crimson amabilis, Ckll. (Tro- 



(^J Joiut 5 nearly as broad as 3 ; insect black, [pical Mexico.) 



apex of (S abdomen truncate arizonensis, Ckll. 



[(Arizona.) 



These will stand as typical Ceratina^ though perhaps 

 amabilis (with eximia, Sm.) might be separated subgeueri- 

 cally. The series will also doubtless be found to include 

 nigra, Ilandl., hispinosa, Ilandl., nitidula, Mor., and parvula, 

 ►Sm. 



The species with 6-jointed maxillary palpi separate thus : — 



(A) Black, with yellow markings; joint 4 of 



maxillary palpi abjut equal to 5 hieroylyphica, Smith. 



(B) Blue or green. [(India, China.) 



(1) Apex of J abdomen moderately broad, 



rounded, with a sharp tooth on each side ; 



insect very biight blue or green viridissima, D. T. 



(2) Xo lateral teeth at apex of abdomen ; insect [(India, Burma.) 



dark green or blue. 

 (a) Apical portion of J abdomen broader 

 than long, 

 (i) Apical portion very broad; hind femora 



of (S triangular tejonensis, Cresson. 



(ii) Apical portion not so broad ; hind [(U.S.) 



femora of S normal dupla, Say. (U.S., 



{b) Apical portion of J abdomen narrow or [Mexico.) 



pointed, 

 (i) Hind femora of J triangular ; second 



subraarginal cell subtriangular. [Mexico.) 



(a) 5 with a light mark on clypeus . . nanula, Ckll. (New 



O) $ with clypeus dark submaritima, Ckll. 



(ii) Hind femora of J normal; second [(WashingtonState.) 

 submarginal cell subquadrate ; $ with 



clypeus dark cijanea, Kirby. 



[(Europe.) 



Here, are three diirtinct series — the first consisting of the 



