120 1\IK. w. K. PARKER ON THE STRUCTURE AND 



The condyle for the mandible {q.c) is large, oblique, and reniform, and has the inner 

 trochlea twice the size of the outer ; the hinder and outer fork of the pterygoid bone 

 runs vertically, splint-like, inside this far-retreated part of the suspensorium. The 

 large Eustachian opening (fig. 6, eu.) is, by this, made to tui-n backwards, as well as 

 outwards ; its hind margin is a thick fibrous ligament. 



The mandible (fig. 7) is quite normal and of great length, answering to the extent 

 of the gape; the mento-Meekelian part (m.mk.) is large, and so is the cylindroidal 

 condyle (ar.c.) ; the cartilaginous bar (mk.) is but little affected by the trough -shaped 

 "articulare" (ar.) ; the dentary (d.) is a little more than half the length of the 

 mandible. 



The "annulus" is very remarkable ; it is large (Plate 23, fig. 7, a.ty.), thick at the 

 edges, oblong in shape, and whilst one horn is attached to the fore part of the 

 portico foiTned by the squamosal (sg.) over the tympanic cavity, the other horn passes 

 behind and under the hind part; its position is oblique, being carried backwards, 

 below, b}' the suspensorium and its splint (g., sq.). 



The stapes (fig. 10, st.) is thick and of a short-oval shape, with the fore margin 

 emarginate. The columella fits by its thick, bilobate, scooped apex, within and around 

 the fore part of the stapes. The inter-stapedial {i.st.) is represented by the larger, 

 unossified lobe ; but it is doubtfully segmented. The medio-stapedial (m.st.) has also 

 some cartilage on the lesser lobe, and the thick bony end carrying the cartilage is 

 almost discoidal. The narrow^ shaft is bent almost at a right angle on the dilated 

 proximal part, and runs more than half way to the distal end. That end, gradually 

 thickening to its middle, is the extra-stapedial (cat.) ; at first it is merely a continuation 

 in the same line as the shaft, but its distal two-thuxls is bent down at a little more 

 than a right angle, is thick below, and cochleate above. There is no supra- stapedial. 

 This generalised, but large, columella is seen (fig. 7, e.st.) to emerge from the cleft, 

 and then to pass, downwards and outwards, inside the membrana tympani. So far 

 are these parts carried outwards, backwards, and downwaixls, that in the upper view 

 (fig. 5, a.tjj.) they are scarcely seen when the eye is focussed to the upper face of the 

 skull; hence the apparent minuteness of the annulus in the figure showing that aspect. 



I could find no cartilage in the hyoid arch from the Eustachian opening downwards 

 until I reached the hypo-hyal region. There (fig. 8, h.hy.), there is a falcate hypo-hyal 

 lobe which passes backwards and inwards to a basal plate of normal size {h.h.hr.), and 

 with the usual small posterior wings, and bony, divergent thyro-hyals {t.hi/.); but there 

 are no anterior wings to the basal j^tlate. Here the absorption of the hyoid band is 

 equal to what is seen in Pipa. 



The investing bones, like those of the endocranium, are very unlike what we see 

 in liana, and in the "Ranidis" generally. 



The fronto-parietals (f-J^-) just overlap the fontanelle and the side-walls of the cranial 

 cavity ; they are almost square over the hind part of that cavity, and then expand 

 forwards to their end. Tlieir hind margin has a pair of shallow notches, and theii' fore 



