MADAGASCAR FROGS OF THE GENUS MANTIDACTYLUS. 257 



16. On the Madagascar Frogs o£ the Genus Mantidactylus 

 Blgr. By G. A. Boulenger, F.H.S., F.Z.S. 



[Received September 18, 1918 : Read October 22, 1918.] 

 (Published by permission of the Trustees of the British Museum.) 



Index. 

 Geographical : Page 



Madagascar Frogs 257 



Systematic : 



Mantidactylus, Synopsis of Species 258 



M. amhohimitomhi, sp. ii 260 



Agli/ptodactyliis, g. n., for Limnodytes niadagascariensis 



A. Dum 261 



Among the B:iany peculiar featui-es of the herpetological fauna 

 of Madagascar is the fact of the genus Eana, so numerous in 

 species in Continental Africa and the Indo-Malayan Region, 

 liaving only two representatives : Ji. {Tonwpterna) lahrosa Cope, 

 allied to the South African R. natcdensis A. Smith, and E. {Pty- 

 chadena) mascareniensis D. & B., distributed over the greater 

 part of Africa, the Seychelles and the Mascarenes included. 



Most of the Madagascar frogs originally referred to Bana or 

 Liinnodytes {Hylorana) have proved to be distinguished by the 

 presence of an intercalated bone between the penultimate and 

 distal phalanges of the fingers and toes and have been referi-ed to 

 an autochtonous genus, Mantidactylus *. In the species grouped 

 by me under this genus, the swellings or discs in which the 

 fingers and toes terminate bear on the lower surface a ring-shaped 

 groove, defining a circular or transversely elliptic area, thus afford- 

 ing a further distinctive character by which to recognise them 

 among those species of Rana in which digital discs are likewise 

 present. 



One species, Limnodytes viadagascariensis A. Dum. [R. ingioi- 

 nalis Gthr.), which I had left in the genus Rana, has been shown 

 by the late Dr. F. Mocquard to be also provided with the inter- 

 calary phalanx and therefore i-eferred by him to Mantidactyhos ; 

 but as in this species the small digital terminal expansions are 

 devoid of the groove to which I now draw attention, I consider 

 it to be entitled to generic distinction, under the new name of 

 Aglyptodactylus. In this A. madagascariensis, the omosternum 

 is forked at the ba§e, as in Mantidactylus, the nasal bones are 

 small, oblique, and separated from each other as well as from the 

 frontoparietals, and the terminal phalanges are obtuse ; there are 

 no femoral glands. 



W6 are now acquainted with 22 species of Mantidactylus, to 

 which a twenty-third is here added. A key to the identification 



* Ann. & Mag. N. H. (6) xv. 1895, p.- 450. 



