HARDWICKE'S SCIENCE. GOSSIP. 



Gl 



It is found almost everywhere during spring, 

 summer, and autumn, but owing to its very ordinary 

 appearance, it usually passes unnoticed. It is 

 variable in size, being sometimes nearly as large as 

 a house-fly, but oftener only half the size. It is of 

 a bright brown colour, covered with long black 

 bristles, and has large wings. The head, too, is 

 large ; and the face, which is yellowish-white, is 

 somewhat swollen. The antennae are prominent, 

 and of a rather unusual shape ; but the most cha- 

 racteristic feature, the one by which the fly may be 

 recognized immediately, is the mouth. A drawing 

 of the insect is given at Cg. 2S, which shows the 



Fig. 29. Mouth of Stomoxys calcitrant, x 14 diam. : ph, ph, 

 pharynx ; Ibr, labrum ; /, lingua ; la, labium j mp, maxil- 

 lary palpi ; le, levers or fulcra of labrum. 



long proboscis. It is only the labrum or lower lip 

 which is so developed in length ; all the other organs 

 are very short. It is apparently jointed in the 

 middle ; but the part beyond the bend is really the 

 sucking part, i.e. the lobes of the labrum, enor- 

 mously lengthened, which, just as in all other flies, 



^^^i 



Fig. 30. Wing of Tachina virgo, x 5$ diams. Names of 

 veins:— co, costal; sc, sub-costal; 111, mediastinal; r, 

 radial; cu, cubital; pr, prsebrachial ; po, post-brachial ; 

 an, anal ; dt, discal-transverse ; d, discoidal areolet ; axl, 

 axillary lobe ; al, alula. 



are capable of being folded back under the head : 

 the specific name geniculates, " having a knee," refers 

 to this folding back. This very peculiar form of 

 mouth shows the relation of the fly to some mem- 

 bers of the family Conopidae, which have similar 

 mouths. 



The next two insects chosen for description be. 

 long to the sub-family Muscides. During the warmer 

 half of the year, a remarkable fly may often be seen 

 on trunks of trees, hedges, umbelliferous flowers, 

 and other places where flies congregate. Its colour- 



ing is simple, but exceedingly striking : the body is 

 of a very dark steel-blue — almost black, smooth 

 and lustrous ; the wings are grey at the tip, and 

 brilliant orange at the base and along the fore 

 border for about half their length. The face is of 

 a yet more brilliant and golden colour than the 

 wings. The bright orange, so well set off by the 

 deep colour of the body, gives the fly its beauty, and 

 makes it much more handsome than the Blue-bottle, 

 which it resembles in shape and size. This fine in- 

 sect is known as Musca meridiana ; and, as its name 

 tells.it is only to be met with during the most sunny 

 part of the day. 



Fig. 31. CorJi/lura puhera, x 7 diam. 



The mouths of the Muscidae are all interesting, 

 but that of 31. meridiana is pre-eminently so. It is 

 short and thick, and the sucking part of the labrum 

 (i.e. the part often erroneously called " the lips ") 

 is enormously broad, in great contrast to the mouth 

 cf Bucentes. The capillary channels are large and 

 numerous, and the whole mouth is hairy. It is also 

 remarkable for possessing two little papillae, which 

 appear to be the rudiments of missing organs, — 

 labial palpi, perhaps. 



Our next fly, Stomoxys calcitrans, is common from 

 April to October, and especially so in the late summer 

 and autumn. It greatly resembles, in external fea- 

 tures, the common house-fly, but it is unlike it in 

 one or two important points which we "ill briefly 

 notice. The name Stomoxys calcitrans is most 

 appropriate: the former word signifies " sharp- 

 mouth," referring to the structure of that organ, 

 the latter " spurring," in allusion to its use. Eig. 29 

 shows the mouth, which is remarkable for this, that 

 whereas most biting flies use only the labrum and 

 maxillae for piercing, this fly bites with the labrum 



