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Show 286 MR. ST. GEORGE MIVART ON ANUROUS BATRACHIANS. [May 13, each other by the tongue being fixed in front as usual (the Enyy-stomidee) or free in front (the Xenorhinidee). The toothed (or Frog) series may also be similarly divided into two sections :-first, those with an imperfect ear, the Bombinatoridee; secondly, those with a perfect ear. This latter section contains more families than any other section of the order, there being three families in which the sacral vertebra is not dilated, and four in which it is dilated-seven in all. In order, however, to place those families in juxtaposition which have most affinity for each other (e. y. the Discoglossidee next to the Ranidce, &c.) I have thought it desirable, in the annexed table, to treat the dilatation of the sacral vertebra as subordinate to the presence or absence of parotoids. I do not, however, consider, as I have already said, the latter character to be inferior in importance; but such a way of treating the matter is convenient in this particular instance. Thus the Plectromantidce, with parotoids and non-dilated sacial vertebra, will come first, then those with parotoids and dilated sacral vertebra; first, the Alytidee, without digital disks, and then the Pelodryadidee, with them. Of those without parotoids the Hylidce have a dilated sacral vertebra and digital disks ; while undilated sacral vertebra is common to the Polypedatidce and Ranidce, which differ in the presence or absence of the disks; after these the Discoglossidee, which have the sacral vertebra dilated, but are devoid of disks. Finally come Pipa and Dactylethra, which thus form a third primary division of the Anura, characterized by a highly developed tympanum, but no tongue. ANURA. A. Without maxillary teeth at any time of fife, but with a tongue. I. Ear imperfect. Tongue free in front Rhinophrynidee. Tongue fixed in front Phryniscidce. II. Ear perfect. o. Sacral vertebra not dilated Hylaplesidce. JJ. Sacral vertebra dilated. 1. Parotoids Bufonidee. 2. N o parotoids. Tongue free in front Xenorhinidee. Tongue fixed in front Enyystomidce. B. With maxillary teeth at some time of life and with a tonyue. I. Ear imperfect Bombinatoiidee. II. Ear perfect. a. Parotoids. 1. Sacral vertebra not dilated ... Plectromantidce. 2. Sacral vertebra dilated. No digital disks Alytidee. Digital di>ks Pelodryadidee. |
