NATURAL SCIENCES OP PHILADELPHIA. 295 



posed to them — the Gallinas. Their typical forms, like the last, are distributed 

 to the Neotropical and Australian regions : the outliers (pigeons) are not so 

 numerously distributed in the other regions. 



The Struthious birds, the most synthetic of the class, belong exclusively to 

 the Southern Hemisphere ; as is well known, they chiefly abound in Austra- 

 lia and its adjacent islands, with an abundant outlying type — the Tinamus— 

 in South America. 



The penguins, which only of all birds display the divided metatarsus, in- 

 habit the Antarctic regions and Cape Horn. 



The Clamatarial type of the Passeres exhibit larval characters in the non- 

 developmeht of the singing apparatus, and the scaled or nearly naked tarso- 

 metatarsus. These are chiefly South American. 



Of Mammalia, the placentals without enamel on their teeth, which, in this 

 respect, never reach the full development of the class, whose dentition is also* 

 monophyodont, i. e., the Edentata, inhabit only the Southern Hemit^phere, 

 and almost altogether the Neotropical region. The implacental Mammalia, also 

 (except in one tooth) mononhyodont, which approach birds and reptiles in so 

 many respects, are confined to the Southern Hemisphere, and chieflj^, as all 

 know, to Australia. 



Of the Quadrumana, the Platyrrhine group is known to be inferior to the 

 Catarrhines : the farmer presents an entirely embryonic condition of the os 

 tympanicuvi, which is passed by the latter in early age ;* it contains also the 

 only clawed genus of the true monkeys. It is confined to the Neotropical. 

 To Madagascar, also of the Southern Hemisphere, and nearest in many ways 

 to the Neotropical, pertain the lowest families of the Quadrumana, the Lemur- 

 idc'« and Chiromyidae ; the former presenting brains without convolutions, 

 and approaching in many ways the Insectivora; the last imitating, at least, 

 a Rodent. 



There are also other reasons for the inferiority of South America. Its deer, 

 which are few, are those which never produce more than the " dague," or the 

 first horn of the northern Cervus, or those which never get beyond the fourth 

 step in the development of the lower group ofR. Nearctica. 



The LoricariidfB of South America, I am informed by Prof. Agassiz, possess 

 the foetal pupil of the vertebrate type. 



If we glance at Coleoptera we find the great predominance of the groups 

 ■with undeveloped tarsus, the three and four-jointed Trimera and Tetramera, 

 and of the lower group with undeveloped sternum,f the Rhynchophora, in the 

 Neotropical region. 



Among Lepidoptera it is known that the most gigantic of the species of 

 the Neotropical region are Noctuidre (Erebus, etc.), and that in that region 

 this low type of the order reaches its greatest development. The largest 

 forms of theRegio Nearctica, as well as Palzearctica, are representatives of 

 the higher type of the Saturniidae (Attacus, Telea, etc.), while the largest and 

 most powerful of this order in the Palfeotropical (Indian) region are the 

 Papilionid forms of Ornithoptera, etc., the generally admitted crown and 

 head of all. Of course other types, both higher and lower, are largely de- 

 veloped in each and all of these regions, and the significance of the above 

 facts is perhaps only to be seen when taken in connection with a large num- 

 ber of others pointing in the same direction. 



Two or three comparisons of different fauna may be brought forward final- 

 ly. First, returning to the birds, a survey of some of the differences between 

 the birds of Panama, Pennsylvania and Palestine may be made. J 



Tristram noticed 322 species of birds within the range of the ancient terri- 



* See Dr. H. Allen, Proceed. A. N. S., Philada., 1867. 



fLeconte American Association, 1867. 



X From the American Naturalist, 1868, by the author. 



1868.] 



