DEVELOPMENT OP THE SKULL IN THE BATRACHIA. 131 



condyle and a flabelliform body ; its basal piece {b.hy.) is composed of simple car- 

 tilage. 



The basi-branchial (h.hr^.) is a solid cartilaginous disk, with the rudiment of a second 

 {b.br~.) behind it. 



The hypo-bi-anchial {h.br.) is a triangular plate, which passes outside the postero- 

 internal angle of the hyoid, and has articidating with it the four normal " extra- 

 branchials " (ex.br.). They give rise near the lower end to processes tha,t run into tlie 

 septa on the inner and upper surface of the pouches ; these (cbr.) are (all l)ut the last) 

 small rays, with a pedate free end : they are " cerato-branchials. " 



Fourth Family. " Alytid^." 

 Genus Alytes. 



This Family, as enlarged by Professor Mivakt (P. Z. S., 18G9, p. 291), suggests 

 this remark, namely, that that assemblage of characters by which the Alytina, Sea- 

 phiopodina, and Uperoliina are characterised, after all only serves to faggot them 

 together ; and the possession of neck-glands, dilated sacrum, maxillary teeth, and 

 sharp toes by Ah/tes in Europe, by Scaphiopus in North America, and by Hyperolius 

 {Uperoleia) in Australia, proves notliing as to the genesis of these three genera. 



Before all things, in classification, natural geographical grouping has to be looked to, 

 and then afterwards the modification into Famihes, Genera, and Species. 



All the Australian Anura I have dissected, as yet, look to me rather like branches 

 of one Australian stock than scattered scions of Families and genera from distant 

 geographical regions; and whilst appraising at their full value every character that can 

 be discovered in any type whatever, I shall keep as far as possible the distribution of 

 the types before my eyes. The Dog-faced Opossum is far nearer akin to the Kangai'oo, 

 in spite of his canine features and form, than he is to the true Dog of other regions. 



31. Alytes obstetncans. — Adult female ; 1 inch 1 Hues long. Europe.'^' 



The skull of this type is extremely like that of the delicate Australian Tree-frogs, 

 e.g., Hyla Ewingii and H. phyUochroa (see Plate 31) ; whilst in the next instance, 

 an Australian Frog, the skull might be taken for that of one of the " Eanida?," and a 

 not very aberrant form of the European or the Oriental species of Raiia. Yet a 

 careful examination of this skull wdl show that the skull of Alytes has some important 

 points of coincidence with that of Pelodytes and Bombinator; and the Obstetric Frog 

 is more likely to be one branch of the same stock as these other European kinds than 

 a migrated relative of an Australian species, or the Australian species a migi-ated 

 relative of this. 



• My specimens of this Frog arc the gift of Professor Troeschel, of Bonn, 



S 2 



