162 MR. W. K. PARKER OX THE STRUCTURE AND 



not ossify its own alaa ; its axillae are shallow. Although elegantly arched m front 

 the snout is very wide, and the oblique outer nostrils (e.n.) on each side are sub-tubular 

 and very large ; they have outside them well developed labials (u.lKu.l-.). 



The roof and floor (fig. 7, al.n.; fig. 8, s.n.) are very wide tracts of cartilage; there 

 is no prenasal rostrum, and the angles of the floor and the pro-rhinals (fig. 8, s.n., p.rh.) 

 are large, and end in out-turned hooks ; the septum nasi, above and below, is thick 

 and clearly defined. Up to the point where the true palatine cartilage (fig. 8) begins, 

 the ethmoidal wing, which is generally thick and somewhat pointed forwards behind 

 the outer margin of the inner nostril, is here unusally developed, as in the genus 

 Cystignathus (Plate 16) (indeed, in C. Ujphonius it is ossified continuously with the 

 ethmoid, Plate 16, figs. G and 7). Here it is not ossified, but is of great breadth, and is 

 seen outside the post-narial spike of the vomer {n.f., v.) — a part which is also, here, 

 four times its usual size. Beyond the notch which separates the ethmoidal from the 

 palatine rejjions the cartilage is rather feeble and naiTOw, and so is the whole palato- 

 suspensorial arch, except in its quadrate region behind. 



In conformity with this, the two pairs of bones (pa., 2:>(J-), although qmte normal, are 

 slender and rather feebly developed. 



The pedicle (pc^-) is a small osseo-cartilaginous "foot," gliding on the sub-concave 

 facet outside the prootic spur. The angle between the Ibrks of the pterygoid is more 

 than a right angle, and in it we see the large, oval, Eustachian opening [eu.) 



The cartilage of tliis arch is nowhere obUterated except above the joint {q.c.) where 

 the quadrato-jugal [q.j.) has freely grafted itself. 



The condyles are large and normal, the inner convexity being mucli the larger of 

 the two. Outside the suspensorium and its T-shaped splint {sq.) there is a smaUish 

 crescentic annulus (fig. 11, a.tij.); it is three-fourths of a circle, its width and concavity 

 moderate, and its liiuder horn two-fold. The stapes (fig. 11, st.) is oval, and has a 

 boss ; the columella is slender, the partly ossified proximal end is smaller than usual, 

 and there is no inter-stapedial segment. 



The bony rod {m.st.) is almost straight, slender, and partly unossified distaUy ; at 

 that part segmentation has taken place, cutting ofi" the symplectic element, or extra- 

 stapedial. This cartilage {e.st.) is like the bill of a Spoonbill, and has no supra- 

 stapedial fork. The mandible (fig. 9) is quite normal, the condyle {ar.c.) is reniform, the 

 coronoid crest (cir.) is definite, the dentary {d.) is nearly half the length of the ramus, 

 and the mento-Meckelian {m.mh.) rather long. 



The stylo-hyal [st.h.) margining the Eustachian opening is confluent with the auditory 

 capsule ; it passes into a slender cerato-hyal (fig. 10, c.hy.) ; outside its flexure there is 

 a small extra-hyal, and from the arcli there is a long slender hypo-hyal horn {h.hy.), 

 which curves towards its fellow in front of the great pre-basal notch. 



The basal plate (Ij.h.hr.) is of the average width, and withal, veiy long also ; its 

 lateral lobes are narrow, the hinder longer than the front i)air ; these grow outwards 

 and forwards, those outwards and backwards. 



