4 :\rR. "\V. K. PARKER ON THK STRUCTURE AND 



The range of size is greatest in tlie 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 tlie American Bull-frog, much of an old generalised nature ; whilst 

 the smallest, as li. ci/anophlictis and li. pi/gmcea 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 Gaeman, S. W., Esq. ' On Fi.shes and Reptiles of the 



Lake Titacaca.' Cambridge, Mass., U.S. ; Nov. 26, 1875. 

 Anderson, John, M.D., F.L.S., F.Z.S. "On some Indian Reptiles." Proc. Zoo). 



Soc, Feb. 21, 1871, pp. 149-211. 

 Balfour, F. M., M.A., F.RS. '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. Gustap. ' Ueber die Nasenholen und der Thranen Nasengang der 



Amphibien.' Leipzig : 1877. 

 Bridge, Professor T. W., B.A. 



1. " On the Cranial Osteology of Amia calva." Jour, of Anat. and Phys., vol. xi., 



pp. 605-622 ; pi. 23. 



2. "On the Osteology of Poh/odon folium." Phil. Trans,, Part IL, 1878, pp. 



683-733 ; Plates 55-57. 

 Cope, Professor E. 



1. "On the Classification of the Anura." Jour. Nat. Sc. PhU., 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. 

 (^ CuviER. 'Ossemens Fossiles.' Atlas, plate 252. Paris: 1836. 



DuGfes. ' Recherches sur I'Osteologie et la Myologie des Batraciens il leui-s diffdrens 



kges.' Paris: 1834. 

 Garman, S. W., Esq. (Cambridge, Mass., U.S.). 



1. "Peruvian Fishes and Reptiles." Bulletin of the Museum, 1875. 



2. " Fishes and ReptUes of the West Coast of South America." Proc. Bost. Soc. 



Nat. Hist., vol. xviii., pp. 202-205 ; Dec, 1875. 



3. "Reptiles and Batrachians." Ibid., vol. xviii., pp. 402-413 ; June 21, 1876. 

 /' 4. " On Pseudis." A note on the so-called Batraehichthys, tlescribed in the Ann. 



Mus. Nac. Rio de Janerio, vol. i., plate 6, by Dr. Pizarro, 



