200 MR. W. K. PARKER OX THK STRUCTURE AND 



Tilt* f'me j):iit of tlie pterygoid bone is a large trowel (fig. I, pg.), and it has used 

 up the fore half of the cartilage which is its endoskeletal correlate. 



The hinder, forked part, whose forks form a right angle, clamps the pedicle and the 

 quadrate pier; the former (jjd.) is, by it, tied down to the skull, and would be found 

 very small and not quite segmented from the basis-cranii. The latter (figs. 1-3, q., q.c.) 

 is a strong -retreating bar, with a very large trochlea below, and over this some bone 

 derived from the quadrato-jugal {</J.). 



The annulus {a.ty.) is large, thick, strong in the rim, broad, and complete. 



The mandiljle (fig. 3) answers to the strength of the upper face, and is quite 

 normal. 



The stapes (fig. 4, st) is a thick, oblitjue mass of cartilage, projecting externally in a 

 boss ; it is hinged to the columella by a round tooth in the middle of its oblique scooped 

 fore edge. The columella, without a proximal joint, is unossified at that part, which is 

 nearly as long as that in front of the stapes ; it is very oblique, is scooped, and has 

 three teeth-like projections for its hinge in the stapes, so that these parts fit together 

 like the valves of a " Lamellibranch." The shaft, altogether (m.st.), is very gnarled 

 and irregular, with a gentle arch ; its fore end is unossified and is cut oft', by segmenta- 

 tion, from the extra-stapedial. 



That pait {est.) is spatulate, with a thin flange; this edge is notched oft' in front, 

 and ends above in a small supra-stapedial {s.st.), that soon becomes a mere ligament. 



The hyoid band is confluent above (fig. 2, st.h.) ; it is broadish, and widens out 

 below before it turns backwards. Both the "notch" and the basal plate (Plate 38, 

 fig. 5, h.h.hr.) are lai'ge — both long and wide; it has large ear-shaped front, and small 

 styloid hind, lobes; the thyro-hyals {th.h.) are strong, and well bent, upwards, as they 

 embrace the larynx. 



The investing bones are strong and thick, and scabrous externally ; the fronto- 

 jjarietals {/■}>•) are both thick and wide ; they have a square postorbital process, 

 which articulates with the squamosal (•v'/.), ai-e very wide behind, and become narrow 

 from before, backwards. Their oibital part overlaps the endocranium, and doubles its 

 width behind. The fronto-sagittal suture is perfect, tlie fronto-nasal suture almost 

 transverse. The nasals (».) have the normal form and the Bufonine solidity; they 

 meet along the middle, and only leave the end of the snout, and the etlimoidal wings, 

 vHicovered. 



The marginal bones {pw.., wx., q.j.) are normal in form, but veiy strong and steep 

 (fig. 3) ; the maxillary [mx.) has a wide palatine plate, which is widest where it arti- 

 culates with the pterygoid. 



There is a large septo-maxillary (fig. 3, below e.n.) beneath the nostril and inside the 

 maxillary. The squnmosal {sij.) has a large, rough, ear-shaped supratemporal portion, 

 and a long, retreating, descending bar. The parasphenoid (figs. 2, 3, pa.s.) is large and 

 well-formed ; its fore part is attenuated for some distance, the wings are splinteiy 

 and angidar, the hind part broad, and the median part thickened at the cross. 



