odification of the
sphenethmoid-prevomer area. A more detailed study of the cranial
osteology of _Allophryne_, especially the structural relationships of
the sphenethmoid-prevomer area may elucidate the relationships of
_Allophryne_.

The relationships of _Allophryne_ cannot be understood without a
re-analysis of some of the features used as major criteria in frog
classification (the nature of an intercalated cartilage; the nature of
the sternal complex; the relative value of cranial osteology; the
vertebral structure; and the thigh musculature). Some of these features
have been investigated by other workers, most notably Griffiths, but
others have not and need re-examination. A re-analysis of some of the
major criteria used in frog classification is in progress (Callison,
Lynch, and Trueb) and upon completion of that study we think the
relationships of _Allophryne_ will become apparent.

A more comprehensive study of the cranial anatomy of certain hylids,
leptodactylids, dendrobatids, and atelopodids along with that of
_Allophryne_ is needed to clarify the relationships of _Allophryne_,
and might indicate that the recognition of a fifth family is necessary.

CONCLUSION

Among currently recognized families of frogs, _Allophryne_ is least
different from the Hylidae although it is our opinion that inclusion of
this genus in the Hylidae probably represents an unnatural
classification. However, the present evidence suggesting that
_Allophryne_ should be in another family is less convincing than
evidence suggesting it should be in the Hylidae. We tentatively place
_Allophryne_ in the Hylidae.

LITERATURE CITED

DAVIS, D. D. and GORE, U. R.

1936. Clearing and staining skeletons of small vertebrates.
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DUELLMAN, W. E.
1956. The frogs of the hylid genus _Phrynohyas_ Fitzinger,
1843. Misc. Publs. Mus. Zool., Univ. Michigan, 96:1-47,
February 21.

GAIGE, H. T.
1926. A new frog from British Guiana. Occas. Papers Mus.
Zool., Univ. Michigan, 176:1-3, October 14.

GALLARDO, J. M.
1965. A proposito de los Leptodactylidae (Amphibia Anura).
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GRIFFITHS, I.
1959. The phylogeny of _Sminthillus limbatus_ and the status
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NOBLE, G. K.
1931. The biology of the