I.XTRODUCTIOA'. 9 



cardines just outside tlie articulation of the arms of the lorit. 

 1'be maxilla? are sbeath-like organs, each emitting near 

 its centre laterally a palptif: called the ma.rillary palpuK, 

 the number of whose joints varies greatly in the different 

 genera ; two narrow sclerites, called the scleritcs of fhe 

 Injpopharynx, extend from the oral groove, close to the 

 articulation of the cardines, down to the base of the 

 weritum, passing between the rftnxiUie, to whose basal 

 membrane they appear to be attached. In many genera 

 from its point of attachment springs a scale-like organ of 

 variable shape frequently fringed with bristly hairs. Between 

 all the sclerites and organs at the base of the cibarial 

 apparatus extends a membrame limited anteriorly by the 

 fclerites of the hijpoph(ir?/nx, the investing membrane 

 forming a complete bag. 



The whole apparatus can be folded up and p'lcked away 

 in the oral groove thus : — The blades of the maxillx in the 

 higher Apidie fold back on to their stems, the lora fold 

 back between the cardines, and the cardines are drawn up 

 into the groove, so that their dista,l extremities point back- 

 wards. In the short-tongued bees there is no folding of 

 the maxillfe on themselves, so that the point of the tongue 

 when folded up is anterior. 



THORAX.^This, as in other insects, is composed of three 

 segments — the prothorax, me.<othorax, and metathorax — but 

 added to the last of these is the basal segment of the abdo- 

 men or propodcum. The dorsal surfaces of these segments 

 are called respectively the pro not iim, mcsonotum, and mcfii- 

 vvfuin ; the sides the pro, 'mesa, and meta pleurie ; the ventral 

 surfaces the j)ro, meso, and meta sterna. The proihora^x, as 

 a rule, is very short, and often is only represented dorsally 

 by a sort of rim-like collar ; its .sides, however, generally 

 extend nearly to the insertion of the wings, where tliey 

 terminate often in a raised tubercle. In the ants and the 

 rumpilidss the pronutnm is more elongate, not raised, and 

 its posterior margin largely emarginate. In the Anthophila 

 the pronoium is short, but not generally raised or gibbous; the 



