

] HETEROMERA. 99 



tibia together; the claws are long sharp and simple ; this arrangement 

 evidently answers the same purpose as the apparently trifid claw of 

 the Meloe larva; the perfect female deposits her eggs at the entrance of 

 the galleries of certain mason bees belonging to the genus Anthophora ; 

 the young larvae hatch out at the end of September or beginning of 

 October ; they remain in a sort of lethargic state until the following 

 April, without taking food and without changing either in form or size; 

 at this time, however, they become more active, and attach themselves 

 to the male Anthophora, which emerge from the pupae sooner than the 

 females ; it is a very curious fact that some sort of instinct seems to 

 teach them that they are wrong, and, watching their opportunity, they 

 pass from the male to the female bee ; M. Fabre, on examining several 

 cells of the Anthophora, found that in some the egg of the bee floated by 

 itself on the surface of the honey ; in others on the egg, as on a raft, 

 sat the larva of Sitdris; evidently then at the moment the egg is laid 

 the parasitic larva springs upon it ; the egg is devoured after eight 

 days, and on the empty shell the Sitaris undergoes its first transforma- 

 tion, and the slim active larva changes into a white fleshy grub, with the 

 under side so much inflated and distended that it floats easily on the 

 honey with its spiracles raised above it and its mouth just resting on 

 the surface; in this state it remains until the honey is all consumed; 

 it then contracts and changes into a state called by M. Fabre a pseudo- 

 pupa or false chrysalis ; its shape in this condition is oval, and it has a 

 solid corneous envelope, and in colour, consistency, and immobility 

 somewhat resembles a Dipterous pxipa; it remains in this state for a 

 varying time and then assumes the form of an ordinary fleshy larva, 

 with the upper surface convex, the spiracles on the lower side of the body, 

 and the head ard short antennae and legs distinct ; after all these changes 

 it turns into a pupa of much the ordinary type, and in the month of 

 August the perfect insect makes its appearance, having taken nearly two 

 years to pass through all these transformations. 



S. muralis, Forst. (humeralis, F.). Black, fuscous-black or black- 

 brown, with the base of the elytra and the b ise of the first joint of the 

 posterior tarsi yellow-testaceous; the elytra are of ten lighter than the head 

 and thorax ; head large, dilated somewhat behind eyes, thickly, rugosely, 

 and strongly punctured; antennae varying in length in the sexes ; thorax 

 subquadrate, with sides subparallel and base truncate, diffusely and 

 coarsely, but somewhat variably, punctured with a central depression 

 and line ; scutellum large, subtruncate or slightly emarginate behind ; 

 elytra broad at base and gradually narrowed to a point behind, strongly 

 divaricate, more or less coriaceous, rugosely punctured, the punctuation 

 becoming much finer behind ; wings ample, visible from above; legs 

 moderately long and stout, black, with the tibiae and tarsi often more or 

 less pitchy. L. 7-12 mm. 



Male with the antennae much longer than in female and gradually 



H 2 



