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Show 106 ON A NEW SPECIES OF TREE-FROG. [May 17, 2. Description of a new Tree-Frog of the Genus Ilyla, from British Guiana, carrying eggs on the back. B y G. A. B o u le n g e r , F.R .S ., Y .P .Z .S . [Received April 30, 1904.] (Plate Y.) H y l a e v a n s i . Tongue subcircular, slightly nicked behind, slightly free behind and on the sides. Vomerine teeth in a strong transverse series, narrowly interrupted in the middle, between the very large choanfe. Head as long as broad ; snout obtusely pointed, a little longer than the diameter of the orbit; canthus rostralis strong, straight; loreal region very oblique and concave ; nostril much nearer the tip of the snout than the eye ; interorbital region slightly concave, nearly as broad as the upper eyelid ; tympanum very distinct, three-fifths the diameter of the eye. Fingers free; no distinct rudiment of pollex; toes three-fourths webbed, the web reaching the disks of the third and fifth, two last phalanges of fourth free; disks a little smaller than the tympanum ; no tarsal fold. Skin finely granulate above, more coarsely on the belly and under the thighs, smooth on the throat. Brown above, speckled and spotted with darker, limbs with regular dark cross-bars ; white beneath, throat, breast, and limbs speckled with brown. From snout to vent 75 millim. The unique specimen, a female, carries its eggs on the back, fitting into shallow hexagonal impressions in the skin ; these eggs, 22 in number, measure 8 or 9 millim. in diameter, and contain tailed larvae with rudimentary limbs and with allantois-like membranous respiratory organs. In this it agrees with Hyla goeldii Blgr.*, to which it is nearly related, and with Ceratohyla bubalus Esp.f This remarkable Frog was obtained at the end of November, 1902, at Groete Creek, Essequibo, by Dr. R. Evans, who has kindly presented it to the British Museum, together with a sketch made from the fresh specimen, and showing the embryos in position ; these have unfortunately come off in transit. E X P L A N A T IO N OF PLATE V . Hyla evansi, sp. nov. Natural size. * Cf. Boulenger, P. Z. S. 1895, p. 209, pi. x. figs. 1-3. f Cf. Boulenger, P. Z. S. 1903, ii. p. 115, fig. 8. |