Ann. d. Sci. Nat. sér. 6, vii. 1878, Art. 5.
Baldwin Spencer, op. cit. p. 3.
Sörensen, Journ. Anat. and Phys. 1894, p. 127-138.
Moreau, Ann. d. Sci. Nat. sér. 6, Zool. iv. 1876, Art. 8, p. 62.
Erman, Gilbert Ann. d. Physik. xxx. 1808, p. 113.
Ann. d. Sci. Nat. sér. 6, vii. 1878, Art. 5.
Baldwin Spencer, op. cit. p. 3.
Sörensen, Journ. Anat. and Phys. 1894, p. 127-138.
Moreau, Ann. d. Sci. Nat. sér. 6, Zool. iv. 1876, Art. 8, p. 62.
Erman, Gilbert Ann. d. Physik. xxx. 1808, p. 113.