482 



COLEOPTERA. 



spurs ; tarsi without claws, joints each with a membranous 

 lobe beneath." The females are sac-like. They live enclosed 

 iu the body of the bee. 



In Stylops the antennae are six-jointed, and in Xenos they 

 are four-jointed. From the middle of May until late in June 

 both sexes of Stylops may be found in "stylopized" individu- 

 als of Andrena and Polistcs. The flattened triangular head 

 of the female may be seen projecting from between the abdomi- 

 nal segments of the bee, and sometimes there are two or three 

 of them. On carefully drawing out the whole body of a female 



Stylops Childreni (Fig. 456 ; a, ab- 

 domen of bee enclosing the female 

 Stylops ; ?>, top view), which is very 

 extensible, baggy and full of a thin 

 fluid, and examining it under a high 

 power we found multitudes, at 

 least three hundred, of very minute 

 Stylops larvre, like particles of dust 

 issuing in every direction from the 

 body of the parent. Most of them 

 escaped from near the head, over 

 which they ran, as they must do, 

 when the parent is in its natural 

 position, in order to get out upon 

 the surface of the bee. It thus ap- 

 pears that the young (Plate 3, fig. 6, 6 a) are hatched within 

 the body of the parent, and are therefore viviparous. The 

 head of the female is flattened, triangular, nearly equilaterally 

 so, with the apex or region of the mouth obtuse, and the two 

 hinder angles each containing a minute simple 63*6 ; the larger 

 part of the head above consists of the epicranium, which is 

 narrow in front, with the edge convex ; the mandibles are 

 obsolete, being two flattened portions lying in front of the 

 gena and separated from that region by a very distinct 

 suture ; no clypeus or labrum can be distinguished. The 

 mouth is transverse and opens on the upper side of the head, 

 while in front, owing to the position of the mouth, lies the 

 rather large labium and the rounded papilliform maxilla?. 

 The larva is elliptical in form, the head semioval, while the 



Fig. 456. 



