REPORT ON ZOOLOGY, 167 



some valuable characters for distinguishing the species of Fes- 

 perti/ionidte. These are derived from the form of the head, 

 which he refers to thi-ee distinct types ; the form and direction 

 of the auricle, which he refers to seven types ; and the form of 

 the tragus. He observes that in the restricted genus Vesper- 

 tilio, the organs of mastication and motion present but little 

 variation. 



2. ^ves. — The structure of birds in general is perhaps quite 

 as well undei'stood as that of Mammalia, and the leading groups 

 are on the whole better determined. It is also curious to observe 

 that the orders most generally adopted at the present day nearly 

 coincide with those of Linnasus, thus evincing the tact with 

 which that great naturalist in some instances seized affinities. 

 The only alterations which we find in the RPgne Aniin. consist 

 in the union of the two Linnaean orders Picoi and Passeres, (be- 

 tween which it is certainly not easy to define,) and the separa- 

 tion of the Scansorial birds from the former to constitute a 

 distinct order by themselves. It will be well, however, to notice 

 the principal arrangements of this class whicli have appeared 

 since Cuvier's, in some of which we shall find a desire to deviate 

 more widely from the system of Linnaeus. This will also aftbrd 

 an opportunity of pointing out those individuals who have most 

 contributed to the recent progress of this department of zoology. 

 The first is that of Vieillot, which appeared in 1818 in the 2nd 

 edition oiilxeNouv. Diet. cV Hist. Nat. (Art. Ornithologie). 

 Its author was previously well known for his many valuable 

 works on ornithology, in one of which* he had already given 

 a slight sketch of his arrangement. Vieillot' s orders are five in 

 number, and similar to those of Linnaeus, excepting that with 

 Cuvier he throAvs together the PiccB and Passeres to form one, 

 which he calls Sylvicolce. For the terms GrallcB and Anseres, 

 he also substitutes Illiger's names of Grallatores and Natatoi'es. 

 In 1820, Temminck published the 2nd edition of his Manuel 

 d' Ornithologie, to which is prefixed a sketch of a general ar- 

 rangement of birds, professedly grounded on the habits and 

 organization. Perhaps, however, this is the least valuable part 

 of a work, exceedingly rich in practical information relating to 

 this class, and indispensable to ornithologists on all other con- 

 siderations. Temminck's system, which is a slight modifica- 

 tion of that given in the first edition of his Manual, cannot be 

 considered as natural. His orders, amounting to sixteen, are 

 greatly overmultiplied, and are far from being groups of equal 

 value. In fact, he has not distinguished between orders and 



'Analyse d'une nouvclle Ornithuloyie elimentaire. 8vo, Par. 1816. 



