Kingsley.] 
174 
[April 20, 
With the exception of the osteological details given by 
Dumeril and Lunel, there are no anatomical descriptions of an 
additional hind leg among the Batrachia and hence no comparisons 
are possible. In its osteology, in the formation of an acetabulum 
by the two pubic bones, the case under discussion differs entirely 
from every other described case. 
Concerning the many explanations advanced for such monstros- 
ities I have nothing to say. 
Bibliography. 
1. Balsamo-Crivelli, G. — Sovra alcuni nuovi casi di Polimelia (membra 
sopranumerarie) osservati in alcuni individui del Genre Rana. — Rendicon- 
diti Reale Inst. Lombardo, ii, pp. 261-263, 1865. 
2. Cisternas, Raphael. — (No title.) Rev. et Mag. de Zool., 2, xvii, 
pp. 287-288, 1865. 
3. Van Deen, I. Anatomische Beschreibung eines monstrosen sechsfiis- 
sigen Wasser-Frosches, 1838 (cited from Dumeril). 
4. Dumeril, August. — Trois cas de polymelie (membres surnumeraires) 
observes sur des Batraciens du Genre Rana. Comptes Rendus ix,pp. 911. 
913, 1865. 
5. Dumeril, August. — Observations sur la monstruosite dite polymelie ou 
augmentation du nombres des membres chez des Batraciens anoures. — 
c> 
Nouv. Arcli. du Mus. Paris, i, pp. 309-319, pi. xx, 1865. 
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sur un Batracien du Genre Pelobates et sur un espece du genre Raie. — 
Comptes Rendus, lix. pp. 800-802, 1864. 
7. Guettard. — Sur differentes monstr. de plantes et d’animaux. — 
Memoires sur differentes parties des sciences et arts, t. v, le Memoirep. 25, 
pi. xviii, f. 3, 1783 (cited from Dumeril). 
8. Kingsley, J. S. Two headed snakes. American Naturalist, vol. xii, 
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raires) observes chez la Rana viridis seu esculenta (Linn.) — Memoires Soc. 
Phys. et d’Hist. Nat. Geneve, xix pp. 305-312, 1 pi. 1868. 
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