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THE AMEBIC AN NATURALIST [Vol. XL VI 



Indies, are some of the smallest species. The largest existing 

 reptile is the Ganges crocodile, Gavialis gangeticus (Gmelin) of 

 northern India, which is said to attain a length of thirty feet or 

 more. This, however, is insignificant in comparison with that 

 attained by the sauropodous dinosaurs of the Mesozoic. The 

 American genera Atlantosaurus, Brontosaurus, Camarasaurus 

 and Diplodocus were immense creatures. Atlantosaurus im- 

 manis Marsh of the Wyoming Upper Jurassic, supposedly terres- 

 trial from mechanical considerations, is one of the largest land 

 vertebrates which has ever existed, probably upwards of one 

 hundred feet in length. The uncompensated extravagance of 

 energy in the maintenance of such immensity, coupled with the 

 small and primitive brain, were without doubt to a great extent 

 factors in the extinction of these gigantic vertebrates. These 

 animals are without living descendants. 



The familiar "spring peeper," Hyla pickeringii (Storer), 

 about 20-28 mm., of eastern North America is the smallest 

 American Hyla and thus one of our smallest batrachians. The 

 HylidEe, comprising about 150 species, have a practically cosmo- 

 politan distribution with the exception of Africa and the Malay 

 Archipelago. Essentially arboreal, in the dense, steaming 

 tropical forests of South America they attain the highest diver- 

 sity of generic and specific types. H. pickeringii does not ordi- 

 narily ascend into the trees until early in autumn. A number 

 of true frogs are as small or smaller, thus Arthroleptis sechel- 

 lensis Boettger of the Seychelles, interesting from its habit of 

 carrying its eight or nine tadpoles affixed by their ventral sur- 

 faces to its back, is but about 20 mm. in length of head and 

 body. The smallest salamander of the eastern United States is 

 the red-back, Plethodon cinereus erythronotus Green, an elon- 

 gate form of about 75 mm. The largest salamander and the 

 largest existing batrachian is Mcgalobatrachus japonicus (Tem- 

 minck), the giant salamander of Japan, which reaches a length 

 of over five feet. At no time have the Batrachia been the domi- 

 nant type of vertebrate life, either in size or variety of forms. 



It is among the fishes that we find the smallest known verte- 

 brates. Thus, Mistichthrjs luzonensis H. M. Smith, 6 an extraor- 

 dinarily minute goby from Lake Buhi, Luzon, P. I., is accorded 

 this distinction. The average length of this species is 12.9 mm. 

 The average for egg-bearing females which exceeds the average 

 • Science, N. S., Vol. 15, p. 30, Jan. 3, 1902. 



