Y2 Journal New York Entomological Society. [Voi. ix. 



Another interesting fact is this : the life of an individual female 

 bee is eleven months at least, and of this entire period not more than 

 ten days at the outside is passed above ground — probably much less, 

 for only when gathering pollen does the insect come out of its den. 

 How long an individual male lives I do not know, for circumstances 

 prevented the continuation of observations. If it does nothing else, 

 this note proves that an entire season may be not unprofitably spent in 

 studying the habits of even a single species. 



EXPLANATION OF PLATE IIL 



Structural details of ^«^oc/;/o/-rt humeralis Patt., I, anterior leg ; antenna cleaner 

 at o, at 2, yet further enlarged ; 3, middle leg ; 4, the single tibial spur yet further 

 enlarged ; 5, posterior leg; 6, spurs of posterior tibia, more enlarged; 7, claws of 

 anterior tarsus; 8, claws of posterior tarsus; 9, antenna; lo, mandible; II, palmate 

 body hair ; 12, tip of labium showing ligula, paraglossa and palpi ; 13, tip of maxilla : 

 all much enlarged. Original. 



EXPLANATION OF PLATE IV. 



Digging and breeding habits of Colletes and Augochlora. 14, burrow of CoUetes 

 compacta, the well-defined upper shaded portion representing the cast which runs to the 

 end of the upper lateral ; a " heel " extends below this lateral from the main burrow, 

 below which the evenly shaded area represents the sand-filled portion of the digging ; 

 15, brood cell of C. compacta, enlarged about two diameters, showing attachment of 

 egg at sides, its tip resting on the food surface ; 16, 17, casts made from hibernating 

 burrows of Augochlora humeralis, actual length about 50 inches ; 18, cast of breeding 

 burrow of Augochlora, with two small cell clusters of brood cells ; the oblique lateral 

 at top, from which cast was made; lower part of cast broken off"; actual length of 

 portion shown 22 inches ; 19, diagrammatic section, about ^ natural size, showing 

 oblique entrance to the perpendicular burrow ; sand heap at surface, the entrance to 

 the upright closed by a plug ; 20, perpendicular from which lateral extends backward, 

 natural size; 21, cast of a cell cluster with five brood cells: 22, section through a 

 single cell cluster about twice natural size, showing pollen loaf and egg at bottom, 

 the outside cells continued until they almost meet below the loaded cell ; 23, egg of 

 A. humeralis, very greatly enlarged. Original. 



EXPLANATION OF PLATE V. 



Plaster cast in position in the bee mine, ready to take out : has two brood cells. 

 In the bee mine, showing tools and method of digging out casts and investigat- 

 ing burrows : each notch or angle indicates a cast taken out. 



