REVIEWS, 
75 
while the genus founded on Brachystoma longicornis passes over to the 
second. The genus Brachystoma , in the restricted sense, indicates, by the 
length of the pobrachial and anal areolets, the transition to Iiybos. 
10. DoLiCHOPiDiE.—The whole treatment of this family is so judicious 
that it might serve as a pattern for all the rest. The very complete and 
carefully constructed character of the family is marked by clearness and 
precision of phrase, as well as by the prominence given to the really essen¬ 
tial parts. A less vague account of the composition of the abdomen would 
have been desirable; and the peculiar structure of the metatliorax, the con¬ 
cealed position of the spiracles consequent thereon, and the singular manner 
in which both these and the prothoracic spiracles are closed, also deserved 
a mention. What is said in page 146, line 3, of the structure of the 
second joint of the antennas does not apply to all the species. 
11. Lonchopteridze ; 12, PLATYPEziDiE; 13, PipunculidjE. —These 
three small families are sufficiently characterized. The genera Opetia and 
Platycnema are referred to the Platypezidce ; rightly, as we think. 
14. Syephid^e. —This family, so definitely separated from all others, is 
also well characterized here. It might have been stated that the vena 
spuria behind the pobrachial vein is sometimes inconspicuous, sometimes 
entirely wanting, and that the one before the prasbrachial vein also is rather 
indistinct in certain genera, Ascia for example. A very characteristic mark 
of the family, here overlooked, is the unsymmetrical structure of the anal 
appendages in the males. That the majority of the family imbibe the nectar 
of flowers is questionable: quite ‘as many species appear to feed on the 
pollen. 
15. CoNOPiDiE. —The characteristic of this family is particularly scanty, 
although the structure of the oral organs, the veining of the wings, the 
form of the abdomen and the legs, afford abundance of available marks. 
Myopa and Zodion would unite naturally enough with this family, but not 
so with the Muscidce , as they are here placed: this Mr. Walker himself 
admits in the addenda to the third volume. 
16. Muscuxe. —The second volume opens with this family, which has 
here a greater extent than we can approve of. Accordingly, it embraces 
so many variations of structure, that the characters given are necessarily 
very scanty, and will scarcely help a beginner much. What the author 
means when he terms the wings “ confertae” we do not understand ; and it 
is to be observed that the posterior angle of the wings is not by any means 
rounded off in all the genera. One of the few characters universally appli¬ 
cable to the family has been omitted; that is, the preponderance of the dorsal 
