382 INSECTA, 
The body is short, tolerably broad, flattened and defended by a 
solid skin almost of the consistence of leather. The head is more in- 
timately united to the thorax than in the preceding families. The 
antennze, always situated at the lateral and anterior extremities of the 
head, sometimes form a tubercle bearing three setze, and sometimes 
little hairy laminze. The eyes vary as to size; in some species they 
are very small. 
M. Leon Dufour, in his description of the Ornithomyie bilobee, 
has observed, that although this genus has had ocelli attributed to it, 
he has not been able to discover them. A fresh examination of such 
species as I could procure has in fact convinced me that we were 
mistaken*, and it may be considered as a general rule that the Pupi- 
para are destitute of those organs. The thorax presents four stig- 
mata, two anterior and two posterior. The learned entomologist 
just referred to, in the Hippobosca equina of which he has described 
the Anatomy—Ann. des Sc. Nat., VI, 299, et seq.—could only find 
the two first, those which are situated on the lateral and anterior ex- 
tremities of the mesothorax; but 1 have discovered the two others in 
the same Insect. They are situated, as in other Diptera, near the 
origin of the halteres. The abdomen of the Hippobosca ovina—see 
Melophagus—presents ten, in the form of little round, corneous, um- 
bilicated tubercles, the four last being approximated to the anus. 
Those of the thorax, always four, are very apparent. According to 
the same observer, the interior of this part of the body in the H. 
equina presents both utricular and tubular trachze; but those of the 
abdomen are all of the latter description and very numerous, 
The wings are always distant and accompanied by halteres. Their 
edge is more or less fringed with cilia. The superior nervures which 
are in its vicinity are strong and very distinct; but those which then 
extend to the posterior margin are but slightly marked and are not 
united transversely. In the last Diptera of this family, these organs 
are wanting or are merely rudimental. The halteres also disappear. 
The legs are very distant and terminated by two robust nails with 
one or two teeth beneath, which makes them appear double or triple. 
The skin of the abdomen is formed of a continuous membrane, so 
that this part of the body is susceptible of being distended and of ac- 
quiring a considerable volume, as necessarily happens in those female 
Hippoboscz, where the Jarvee are hatched and continue to reside until 
the period of their transformation into pup. At this epoch the larvee 
issue from the venter of the mother in the form of a soft, white egg, 
almost as bulky as the maternal abdomen; the skin hardens and be- 
* Dr. Leach, however, admits that they exist in certain species. 
