144 :mr. w. K. PARKER ON THE STRUCTURE AND 



12. Columella extremely minute, generalised, and completely ossified. 



13. The two cerato-hyal centres, the short basal plate, and the minute size of the 

 antero-lateral lobes. 



I might, perhaps, add 



14. A single fontanelle. But this is doubtful ; there is only one in Bomhinator. 



I. A. i.— PLATYDACTYLA. 

 First suh-division. — Tree-frogs with narrow sacral apophyses and no neck-glands. 



First Family. Polypedatid^, 

 First genus. Polypedates. 



35. Polypedates chloronotus. — Adult male ; 2 inches long. India. 



The difference between this skull and the next (Plate 26, figs. 1, 2 ; and Plate 27, 

 figs. 1, 2) lies mainly in its general form ; its shape Is half a long ellipse, and the 

 length is to the breadth as 8^ to 7| — an almost exact reversal of the proportions seen 

 in the other. 



The mid and hind skull are greatly affected in their sliape by this, the parotic pro- 

 jections being much less and the orbital region much longer; it is also much narrower. 

 The nasal region has lost little of its breadth, but the ethmo-palatines are shorter 

 and lie within less divergent maxillaries ; its three fontanelles are normal. The 

 occipital condyles (Plate 26, figs. 1, 2, oc.c.) are very similar in both; they are oval, 

 ])osterior, and separated by a concave emargination, which is narrower in this species 

 than in the othei*. Here the ossification is more intense in tlie hind skuU ; the bony 

 masses of the two sides {pr.o., e.o.) are confluent both above and below, and there is 

 scarcely any cartilage left — it is only seen at the outermost part where the pedicles 

 articulate — and the bone reaches half-way between the foramen ovale and the foramen 

 opticum (V., II.). But the girdle-bone (eth.) is somewhat more restricted, and only 

 reaches to the middle of the orbits ; likewise in front it does not run along the 

 .septum nasi, but the whole bone stops short a little behind tlie margin of the proper 

 ethmoidal region. 



The sinuosity of the bounding lines of the mid-.skull is similar in both, but the 

 curves are gentler in this narrower skull. The actual breadth of the nasal roof and 

 floor is but little less in this kind, and the snout is moi'e directly transverse as in 

 Rhacophorus maximus (Plate 26, figs. 5, 6). The pro-rhinals (fig. 2, 2J.rh.) are large, 

 and the septum nasi (s.n.) is very thick and solid, as is seen botli from the upper and 

 lower surfaces. The double palato-suspensorial bow (with its outworks) is rather 

 tightly drawn ; and the quadrate hinges {<]■<'■) retreat a little less than in the next kind. 



