Insects. 1447 



but 1 regret that I did not at that time avail myself of so favourable 

 an opportunity of tracing the history of the bee. Observation has 

 proved to me that the egg first deposited is not necessarily the first to 

 arrive at maturity ; and it must be observed, that in the instance of 

 Xylocopa, and also of Chelostoma, excavating in an upright post, the 

 insect is necessitated to make an outlet both at the top and bottom, at 

 the latter for the purpose of getting rid of the sawdust as she proceeds 

 upwards, and at the former as an entrance when she is forming her 

 cells, and depositing the food for her young brood. 



Genus. — Heriades, St. Fargeau, Spinola. 

 Apis, Linnaeus, Kirby. Trachusa, Jurine. Anthidium, Panzer. 



Body elongate : maxillary palpi 2 -jointed : labial palpi 3-jointed, 

 the second joint being very long : fore-wings with two complete sub- 

 marginal cells. 



Only two species of this genus have hitherto been discovered in this 

 country ; the H. truncorum and H. campanularum : the first of these 

 is the type of the genus ; it is the Apis truncorum of Linnaeus, 

 an authentic specimen of which insect is preserved in the Linnean 

 cabinet. 



Sp. 1. Heriades truncorum. 



Female. — Length 3^ lines. Black, coarsely punctured ; head as 

 large as the thorax, mandibles carinated above, and acutely bidentate ; 

 a patch of whitish hair on each side of the clypeus ; the cheeks at their 

 extreme inner margin bidentate ; the thorax thinly clothed at the sides 

 with white hairs ; the wings fuscous, the basal joint of the posterior 

 tarsi clothed beneath with reddish yellow hair ; the abdomen cylin- 

 dric, the base concave, with a transverse carina along the upper mar- 

 gin ; all the segments have a narrow white marginal band, the first 

 generally interrupted, the apical segment thinly clothed above with 

 short pale yellow hair, the abdomen beneath densely clothed with red- 

 dish yellow pubescence. 



Male. — Length 3 lines. Black, coarsely punctured; the cheeks 

 unarmed, the face clothed with pale yellow hair ; the antennae filiform, 

 nearly as long as the head and thorax ; mandibles not carinated ; the 

 thorax thinly clothed with pale hair; the abdomen inflexed, concave 

 at the base, the first and second segment have a narrow white marginal 



