98 HORSE AND CATTLE FLIES. 
what horny or membranous thread, capable of great extension, and 
also very flexible at the extremity.* 
The thoraa (or body between the wings) slanting off at the shoulders, 
which have each a large patch or irregular ring of tawny-yellow above, 
with more or less of the brown ground colour in the centre, some small 
pale markings along the middle of the hinder part of the thorax, and 
a pale spot in the centre of the scutellum (that is, of the small portion 
of the upper part of the thorax just preceding the abdomen). 
Abdomen brown, grey below, and, like most of the fly, more or less 
beset with bristly hairs. 
Wings two, strong and membranous, slightly opaque and brownish 
in colour, and furnished with several strong dark veins placed along 
the front portion of the wing, as exactly figured from life at p. 95. 
The halteres, or poisers, of moderate length, and with a thickened head, 
but not noticeable without removal of the abdomen. 
Legs rather long (when extended flatly in horizontal movement of 
the insect they appear very long); of great strength; colours tawny- 
yellow, clouded or ringed with brown or black; the thighs mostly brown, 
with a ring of tawny near the extremity; and the two posterior pairs 
of shanks mostly tawny-yellowish in the middle, with a ring of brown 
at each extremity. 
Each foot (or tarsus) is terminated by a pair of claws, and each of 
the pair is formed of one large, very strong, much curved, black claw, 
at the outside of which is placed another much shorter and thicker, 
forming a kind of thumb-like appendage to the main claw. On placing 
the curved claw in a good light, I found that the lower parts of the 
sides were furrowed by minute grooves placed parallel to each other, 
also that the lowest part of the claw had running beneath it a regularly 
serrated or scalloped edge, each groove running down to a notch in 
the saw-like edge (see Plates, and also following figure). Thus, when 
the fly exercises its power of pressing the sides of the curved claws 
together, they form a pair of flat-sided forceps, than which nothing 
could be more perfectly adapted for holding fine objects, like the 
* The number of sete of which this trunk is composed is differently given by 
various investigators. Latreille gave it as two, Duges as four, and Prof. Westwood 
as three; for detailed account see ‘Classification of Insects,’ by Prof. Westwood, 
vol. ii. pp. 582, 583. In my own observations it has appeared to me that the great 
power of sweeping surfaces possessed by the flexible end of the trunk pointed to 
possible drawing-in of fiuid for food from the surface of the skin of infested animals, 
as well as from beneath it, and may (if examined into) confirm the popular belief 
of the Forest Flies imbibing skin perspiration as well as sucking blood.—E. A. O. 
+ The presence of the single pale spot on the scutellum is one of the especial 
differences between the H. equina, Linn., and the H. canina, Rondani. See‘ Muscaria 
Exotica Musei Civici Januensis,’ by Prof. C. Rondani, Annali del Mus. Civ. di Se, 
Nat. di Genova, vol. xii. p. 164, 
