4 
MR. W. K. PARKER ON THE STRUCTURE AND 
The range of size is greatest in the genus Rana, the highest or main typical form; 
here we see that a Frog, as a Frog, should not be too large, nor too small; the largest 
have in them, as the American Bull-frog, much of an old generalised nature ; whilst 
the smallest, as R. cyanophlictis and R. pygmcea of the Oriental region, and some very 
small kinds of true Frogs in both the Neotropical and Ethiopian regions, are mani¬ 
festly kinds that have been arrested at a stage similar to that seen in similar-sized 
young of the typical or medium species. 
BIBLIOGRAPHY. 
I here append a list of papers and works that have been of service to me in the 
present work ; there is here no pretence of completeness, and several of the works 
treat of other types of Ichthyopsida :— 
Agassiz, Professor A., and Gasman, S. W., Escp ‘ On Fishes and Reptiles of the 
Lake Titacaca.’ Cambridge, Mass., TJ.S. ; Nov. 26, 1875. 
Anderson, John, M.D., F.L.S., F.Z.S. “On some Indian Reptiles.” Proc. Zool. 
Soc., Feb. 21, 1871, pp. 149-211. 
Balfour, F. M., M.A., F.R.S. 4 On the Development of Elasmobranch Fishes.’ 
London: Macmillan and Co. 1878. 
Bell, Thomas, F.R..S. ‘A History of British Reptiles.’ London: John Van 
Voorst. 1839. 
Born, Dr. Gustaf. ‘ Ueber die Nasenholen und der Thranen Nasengang der 
Amphibien.’ Leipzig : 1877. 
Bridge, Professor T. W, B.A. 
1. 44 On the Cranial Osteology of Amia calva .” Jour, of Anat. and Phys., vol. xi., 
pp. 605-622 ; pi. 23. 
2. “ On the Osteology of Polyodon folium.” Phil. Trans., Part II., 1878, pp. 
683-733 ; Plates 55-57. 
Cope, Professor E. 
1. “On the Classification of the Anura.” Jour. Nat. Sc. Phil., U.S., vol. vi. 
2. “Geology of Montana.” ‘American Naturalist,’ July, 1879, pp. 432-441. 
3. “ Erpetology of Tropical America.” Proc. Amer. Phil. Soc., 1879, pp. 261-277. 
Cuyier. 4 Ossemens Fossiles.’ Atlas, plate 252. Paris: 1836. 
Duges. 4 Recherches sur l’Osteologie et la Myologie des Batraciens a leurs differens 
ages.’ Paris: 1834. 
Garman, S. W., Esq. (Cambridge, Mass., U.S.). 
1. 44 Peruvian Fishes and Reptiles.” Bulletin of the Museum, 1875. 
2. “Fishes and Pteptiles of the West Coast of South America.” Proc. Bost. Soc. 
Nat. Hist., vol. xviii., pp. 202-205 ; Dec., 1875. 
3. 44 Reptiles and Batrachians.” Ibid., vol. xviii., pp. 402-413 ; June 21, 1876. 
4. 44 On Pseudis.” A note on the so-called Batrachichthys, described in the Ann. 
Mus. Nac. Rio de Janerio, vol. i., jilate 6, by Dr. Pizarro. 
