us 



HARDWICKE'S SCIENCE-GOSSIP. 



is usually about ^ of an inch in length, and is less 

 stoutly built than the rest of the Tabauidae. The 

 wings are nearly as long as the whole body, and 

 therefore, when folded, they project beyond the tip 

 of the abdomen; they are clothed with hairs of 

 various shades of grey, which give them a pretty 

 mottled appearance. The general venation of the 

 wings is similar to that of Tabanus figured, but 

 there is a remarkable short branch projecting back- 

 wards from the cubital vein at the spot marked * in 

 fig. 94 ; this is a feature characteristic of the genus. 



Fig. 



92. Golden-eyed Gad-fly (Chrysops ccecutiens), female; 

 x 3 diams. A. Natural size. 



The antennae are long, and project forwards from 

 the head in a horizontal position : they are so 

 fragile that the insect must be handled with great 

 care during dissection. A drawing of an antenna 

 of a male is given at b, fig. 93. It consists of six 

 joints : in the female the basal joint is narrower 

 than in the male. The eyes are coloured with alter- 

 nate zigzag bands of metallic green and purple, and 

 are very pretty. The mouth is interesting, and the 

 entomologist should not fail to mount a slide or two 

 of it for the microscope. The lancets are of con- 

 siderable strength, and are capable of inflicting a 

 sharp prick on the human skin, producing a small 

 irritating swelling which is slow in healing. 



Fig. 95 represents a foot of this insect: it is 

 typical of the feet of the Tabanidae, possessing two 

 claws and one trilobed pad ; the bristles with which 

 the joints are covered are rather short. 



The male of this" species may be immediately 

 recognized by a striking peculiarity of its eyes, their 

 upper halves (which contain the larger lenses) being 

 pale grey, almost white, while the lower halves are 

 of the same colour as the eyes of the female. It 

 may be recognized also by the largeness of the 

 basal joints of the antennae, and by the absence of 

 mandibles from the mouth. To find males of this 

 and other members of the Tabanidae it is usually 

 necessary to sweep with the net among flowers, 

 long grass, &c., as they seldom fly forth, not re- 

 quiring animal food. 



Chrysops.— In company with the preceding 

 insect one often meets with a few specimens of a 

 less common but more conspicuous fly, Chrysops 

 ccecutiens. It is somewhat similar in habits, but 

 differs from the former in having an exceedingly 

 rapid flight, during which it emits a peculiar hum, 

 which is not likely to be mistaken after having been 

 once heard. The sound is deep-toned, and more 

 musical than that of any other insect which we 

 know. Its flight has been described as silent, but 

 we have found it quite the reverse. 



Fig. 93. a, Antenna of Tabanus luridus ; b, Antenna of 

 Hcematopota pluvialis ; c, Antenna of Chrysops ccecutiens ; 

 all x 20 diams. 



Its eyes are most gorgeous, and no more beautiful 

 sight'of its kind can be conceived than the eye of 

 a Chrysops under the microscope. Truly the fly 

 well merits its name of " Golden Eyes." The ground 

 colour is a most beautiful golden green ; this is 

 spotted with patches of purple lake, which, ac- 

 cording to the play of light, seems to be ruby- 

 coloured, indigo, or brilliant orange. 



Fig. 94. Wing of Tabanus rusticus X o diams. 

 Names of Veins.— en, Costal; sc, Sub-costal; m, Mediastinal; 

 r, Radial; cu, cu. Cubital; sa, Sub-apical ; em, Externo- 

 medial ; j>r, Prse-biachial ; po, Post-brachial ; an, Anal; 

 d, Discoidal Areolet; s, Stigma, or Dark Spot ; axt, Axillary 

 Lobe; al, Alula. 



The Chrysops is rather a "knowing" insect, 

 having a habit of keeping behind one's back, which 

 makes it somewhat difficult to catch. When at rest 

 it carries its wings after the manner of a blow-fly, 

 only more widely separated, and is in this respect 

 quite different from the Ilaematopota. It is not 

 so long as the latter fly, but rather broader. With 

 the exception of an interrupted orange-yellow band 



