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Show 1868.] ON PACHYBATRACHUS ROBUSTUS. 557 2. On Pachybatrachus robustus, a New Genus of Anurous Batrachians. By S T . G E O R G E M I V A R T , F.L.S., Lecturer on Comparative Anatomy at St. Mary's Hospital. In examining at the British Museum the Anurous Batrachians of m y own collection, in order to name them correctly, I discovered that the specimen here described was of a kind not present in the collection, that it was also of a kind unknown to Dr. Gunther, and, finally, that, as I believe, the form is hitherto undescribed. It appears to m e to constitute a new genus, for which I propose the name Pachybatrachus, and robustus as its specific appellation. According to the system of classification devised by Dr. Gunther it must be placed in his Ranidce, where its cleft tongue, webbed toes, and edentulous palate and normally placed digits approximate it to Dicroglossus and Phrynobutrachus. It differs from both these genera, however, in its very different habit, its larger size, relatively as well as absolutely much larger and broader head and mouth, its smooth skin and large tympanum. Its toes are less completely and largely webbed than in Dicroglossus, while they are more so than is the case in Phrynobutrachus. The head of Pachybatrachus robustus is very large and broad; the snout is somewhat longer than the eye; the canthus rostralis is not much marked; the anterior end of the muzzle is rounded but not insignificant in vertical extent, and the loreal region is nearly vertical. The eye is rather large, and the upper eyelid is so marked transversely as at first to have somewhat the appearance of being free and notched behind, as in Megalixalus*; but it is really entire, and is not furnished with any process. The tympanum is very large, its transverse diameter nearly equalling that of the aperture of the eye. The crown of the head is nearly flat. W h e n the head is looked at from below, the upper jaw is seen to project forwards somewhat beyond the anterior extremity of the mandible; and the two rami of the latter diverge at an angle of about 60°. There is a slight symphysial tubercle, but the outer margin of each of the notches which define it can hardly be said to rise into a distinct apophysis. The external nostrils are moderate and situated at about the posterior end of the anterior third of a line drawn from the end of the snout to the anterior end of the eye. There are no teeth in the lower jaw; but a range of small teeth runs along the maxillary border. The palate is absolutely edentulous. The choanae are rather large, and the openings of the eustachian tubes are of nearly the same dimensions. The tongue is well developed, and nearly its hinder half is free; it is distinctly notched, or rather the fleshy processes project from its hinder margin, each about 0*1 inch in length. There is no fold beneath the throat or across the chest; but a prominent line (a glandular fold) extends backwards, from the hinder angle of the eye- * Dr. Gunther, Proc. Zool. Soc. 1868, p. 485. |