228 MR. W. K. PARKER ON THE STRUCTURE AND 



equals that of a typical Batrachian whose tail is rapidly shortening ; in others it nearly 

 equals the skull ni' the adult in those high kinds; the ossification especially is 

 defective here, as in some of the dwarfed kinds of Frogs. The foramen magnum is 

 large, and the roof covers it well ; the occipital condyles (occ.) project scarcely at all, 

 and are jJostero- inferior. The roof runs half way to the ethmoidal region, and has no 

 secondary fontanelles ; the great space (Jo.) is as long as the hinder " tegmen," and is 

 very elegant in shape, like the cordate leaf of Nymplicea alha. 



The tegmen- cranii is no wider in front than at the sides, where it is unusually well 

 developed. The ovoidal auditory capsules are well turned outwards, and are large; 

 beyond them the tegmen tympani (t.ty.) is a small squarish lobe, as in the last two 

 kinds. There is a little calcification above (fig. 1) but more below (fig. 2, h.o.), and that 

 tract is wide, and rapidly widens forwards, for the ex-occipitals {f.o.) are only large 

 reniform patches that enclose their own nerves (IX., X.) ; they creep up between the 

 arch and the capsule so as to show a little above (fig. 1). The prootic also {pr.o.) is 

 a curved band just margining the foramen ovale (V.), and creeping along the capsules 

 for some distance above and below (figs. 1, 2).* 



The mid skull is broad, lessening gently forwards, and bulging ; it is moderately 

 high, and is trholli/ Knossijied, as is also the fore skull and nasal region ; this is equal 

 to the hind skull in axial extent ; the mid skull is one-third longer. The large 

 baggy nasal roofs lying back over the eth mo-palatine bar (fig. 1), and the wide trabe- 

 cular floor (fig. 2, on each side of s.n.) are quite juvenile in character; the nostrils 

 (e.n.) are sub-tubular and projecting ; they are wide apart, and protected by the normal 

 valves {it.P.io.I'-.). The rostrum (ji-n-) is also in its Jirst stage, a mere decurved lip of 

 cartilage; the pro-rhinals {j^.rh.) are small and rudimentary. 



The palato-suspensorial arch is delicate, and continues to the pedicle and quadrate 

 {pd., q.), the pre-palatine is sharp, the post-palatine (pt.pa.) marked off" from the ptery- 

 goid by a sharp lobe (a juvenile character), and the ethmo-palatme has a fine thread 

 of ossifying perichondrium under it {e.pa., jxt.). 



The delicate bifurcate pterygoid (pg-) runs along inside the post-palatine bar, gives 

 off a pedate fork for the short pedicle (jid-), and binds itself to the suspensorium (7.) 

 behind ; in its fork we see the small, round Eustachian opening (eu.). 



The quadrate condyle (q-c.) is a perfectly normal trochlea, oblique, with the front 

 elevation small; above it the "orbitar process" (pr.p.) is retained, as an ear-like lobe, 

 which is nearer the condyle {q.c) than the otic process (fig. 1, above (rr.p.) ; this is a 

 rare character. The anniilus {a.ttj.) is large (quite of the typical size), and is very 

 perfect above, as a ring. The mandible (fig. 3) is long and very perfect in all its parts. 



The stapes (fig. 5, st.) is thick, oval, with an oblique, antero-superior, grooved emar- 

 gination for articulation with the columella ; it is also umbonate. The columella 

 (fig. 5) only wants segmentation of the large cartilaginous proximal lobe (m.st.) to 



* Tlic continuous bony tvact rit^lit ;niil left, in the last, is duo, as tliis skull shows, to coalescence of 

 tlir two normal centres. 



