Of a very different kind is the next we have to notice, the Prodromus systematis mammalium et avium of Illiger, published at Berlin in 1811, which must in its day have been a valuable little manual, and on many points it may now be consulted to advantage - the characters of the genera being admirably given, and good explanatory lists of the technical terms of ornithology furnished.
3 Illiger may be considered the founder of the school of nomenclatural purists.
Ac. Sc. Turin, ideas in this are said to have been taken from Illiger; but the two systems seem to be wholly distinct.
28)-step in advance already taken, it is true, by Illiger- -is here placed on indefeasible ground.
Herein the author first assigned anatomical reasons for rearranging the order Anseres of Linnaeus and Natatores of Illiger, who, so long before as 1811, had proposed a new distribution of it into six families, the definitions of which, as was his wont, he had drawn from external characters only.
First he failed to see the great structural difference between the penguins (which Illiger had placed as a group, Impennes, of equal rank to his other families) and the auks, divers and grebes, Pygopodes - combining all of them to form a "Typus " (to use his term) Urinatores; and secondly he admitted among the Natatores, though as a distinct " Typus " Podoidae, the genera Podoa and Fulica, which are now known to belong to the Rallidae - the latter indeed (see Cool') being but very slightly removed from the moorhen (q.v.).
At the same time he corrected the error made by Illiger in associating the Phalaropes with these forms, rightly declaring their relationship to Tringa (see Sandpiper), a point of order which other systematists were long in admitting.
Herein he divided the class A y es into two subclasses, to which he applied the names of Insessores and Grallatores (hitherto used by their inventors Vigors and Illiger in a different sense), in the latter work relying chiefly for this division on characters which had not before been used by any systematist, namely that in the former group monogamy generally prevailed and the helpless nestlings were fed by their parents, while the latter group were mostly polygamous, and the chicks at birth were active and capable of feeding themselves.
Closely related to this bird is another first described by Linnaeus as a species of Parra (see Jacana), to which group it certainly does not belong, but separated therefrom by Illiger to form the genus Chauna, and now known as C. chavaria, very generally in English as the " Crested Screamer," a name which was first bestowed on the Seriema.