10 MORSE ON THE INTERMEDIUM IN BIRDS. 



4. On the Animals which are most Intermediate between Birds and Reptiles. Prof. Huxley. The 

 Popular Science Review, No. xxvm, p. 237 ; being a Lecture delivered before the Royal Institution, Feb. 7- 

 1868. 



5. Further Evidence of the Affinity between the Dinosaurian Reptiles and Birds. Prof. Huxley. 

 Quart. Journ. Geological Soc. of London. Vol. xxvi. 1870. 



6. Untersuchungeu zur vergleichenden Anatomie der Wirbeltheire. Erstes Heft ; Carpus und Tarsus. 

 Prof. Gegenbaur. Leipzig, 1864. 



7. The Dinosauria. Prof. Seeley. The Popular Science Review, Jan. 1880, p. 44; being originally a 

 Lecture delivered at the Scientific Club at Vienna, on the 19th of April, 1879. 



8. On the Tarsus and Carpus of Birds. E. S. Morse. Annals of the Lyceum of Nat. Hist. N. Y., vol. 10 

 Art. vin. Read Jan. 29, 1872. 



9. On the Ascending Process of the Astragalus in Birds. E. S. Morse. Meeting of the American Asso- 

 ciation for the Advancement of Science. Hartford, 1874. 



10. On the Limbs of Sauranodon. Prof. Marsh. American Journal of Science and Arts, vol. xix, 

 Feb. 1880. 



EXPLANATION OF PLATE I. 



Fig. 1. Portion of left leg of embryo Tern. 



jpjg_ 2. " " " 



Fig. 3. <c 



!' jo-_ 4. " " " " " " " 



Fig. 5. Portion of right leg of embryo Petrel. 



Fig. 6. " " left " " " Sea Pigeon. 



Fig. 7. " " " " " " Herring Gull. 



Fig. 8. " " " " " " Eider Duck. 



Fig. 9. " " right " " " Southern black-back Gull. 



Fig. 10. " " " " " " Penguin. 



Fig. 11. " " right wing of embryo Sea Pigeon. 



Fig. 12. " " " " " " " " third finger more enlarged. 



EXPLANATION OF LETTERS. 



Fe, femur ; T, tibia ; f, fibula ; t, tibiale ; /, fibulare ; Jj intermedium ; c, centrale ; ? tarsal bone of the 

 second series ? D, ulna ; H, radius ; u, ulnare ; r, radiale ; 3, 4, third and fourth carpal bones ; I, II, III, IV, 

 metacarpals. 



