528 MODERN CLASSIFICATION OF INSECTS. 
This family is of much smaller extent than the preceding ; the insects 
are of small or moderate size, and their flight is slow and heavy; the 
fore feet in the genus Simulium are kept in a continual movement, being 
evidently employed as feelers. In their general appearance they 
entirely differ from the rest of the family, approaching the following 
tribe. The species of the genus Bibio are remarkable for the great 
diversity in the opposite sexes ; the larve in this genus (fig. 126. 16.) 
are cylindrical worms furnished with twenty spiracles, and with 
transverse rows of short hairs, which serve as points to assist in pro- 
gression, being destitute of feet; they are found in dung. I have 
found them in garden earth at a short distance from the surface, the 
pupz enclosed in smooth oval cells; the pupa (fig. 126. 17.) is naked, 
and has the thorax very gibbose, with the rudimental wings and legs 
very short. (Réaumur, Mém. tom. v. pl.’7.; and De Geer, Mém. tom. vi. 
pl. 27. fig. 12—20. ; Bouché, Naturg. tab. 4. f. 1—10.; Rosel, Abhandl. 
Ins. vol. ii. tab. 7. Muse.) Lyonnet has given a complete illustration 
of Bibio Marci in its different states (Mem. Posth. pl. 7.). Mr. Haliday 
(Ent. Mag. vol. i. p. 179.) has made some interesting ebservations on 
the unequal numbers of individuals of the different sexes of these insects. 
The species of Scatopse are of small size, and are found in out- 
houses, privies, &c.; their larve are long fusiform grubs, without feet, 
having two short points at the sides of the prothoracic and eight basal 
abdominal segments; the body is terminated by two elongated di- 
vergent sete. (Bouché, Naturg. tab. 3. fig. 16—19.). Mr. Walker 
(Ent. Mag. vol. iii. p. 406.) notices having observed myriads of one 
of the species hovering and settling on a larch tree in October. 
The species of Simulium are also of small size (jig. 126.18. S. 
reptans ¢ ) regarded by Curtis as forming a link between the last- 
named insects and Molobrus, but appearing to me to be much nearer 
allied to Ceratopogon, and perhaps, also, as sugge8ted by Fries, to 
Cordyla. They are found in damp marshy places, flying in great 
swarms ; and as all the parts of the mouth are fully developed (as as- 
certained by Curtis), they are enabled to inflict a very severe wound ; 
in fact, some of the species are amongst the greatest torments to 
mankind, as well as to domestic animals. According to Schonbauer 
one of the species (Rhagio Columbaschensis /’.) is one of the greatest 
scourges to man and beast in the Bannat of Temeswar in Hungary. * 
* See Schonbauer’s Treatise, above referred to, and Kollar’s Treatise on Injurious 
Insects, translated, p. 68. 
