GEOLOGICAL SUEVEY OF THE TEERITOEIES. 321 



creatures, in which they are unique among animals. Swallowing their 

 prey entire like snakes, they were without that wonderful expansibility 

 of throat due in the latter to an arrangement of levers supporting- the 

 lower jaw. Instead of this each half of that jaw was articulated or 

 jointed at a point nearlj^ midway between the ear and the chin. This 

 was of the ball-and-socket type, and enabled the jaw to make an angle 

 outward, and so widen by much the space enclosed between it and its 

 fellow. The arrangement may be easily imitated by directing the arms 

 forward, with the elbows turned outward and the hands placed near 

 together. The ends of these bones were in the Pythonomorpha as inde- 

 pendent as in the serpents, being only bound by flexible ligaments. By 

 turning the elbows outward and bending them, the space between the 

 arms becomes diamond-shaped and represents exactly the expansion 

 seen in these reptiles, to permit the passage of a large lish or other body. 

 The arms, too, will represent the size of jaws attained by some of the 

 smaller species. The outward movement of the basal half of the jaw 

 necessarily twists in the same direction the column-like bone to which 

 it is suspended. The peculiar shape of the joint hj which the last bone 

 is attached to the skull depends on the degree of twist to be permitted, 

 and therefore to the degree of expansion of which the jaws were capa- 

 ble. As this differs much in the different species, they are readily dis- 

 tinguished by the column or " quadrate" bone when found. There are 

 some curious consequences of this structure, and they are here explained 

 as an instance of the mode of reconstruction of extinct animals from 

 slight materials. The habit of swallowing large bodies between the 

 branches of the under jaw necessitates the ^prolongation forward of the 

 mouth of the gullet ; hence the throat in the Fijtlionomorplia must have 

 been loose and almost as baggy as a pelican's. Next, the same habit 

 must have compelled the forward position of the glottis or opening of 

 the windpipe, which is always in front of the gullet. Hence these 

 creatures must have uttered no other sound than a hiss, as do ani- 

 mals of the present day which have a similar structure; as, for instance, 

 the snakes. Thirdly, the tongue must have been long and forked, 

 and for this reason : its position was still anterior to the glottis, so 

 that there was no space for it except it Avere inclosed in a sheath 

 beneath the windpipe when at rest, or thrown out beyond the jaws when 

 in motion. Such is the arrangement in the nearest living forms, and it 

 is always in these cases cylindric and forked. 



The giants of the PytJionomorpha of Kansas have been called Liodon 

 proriger^ Cope, and Liodon dyspelor. Cope. The first must have been 

 abundant, and its length could not liave been far from fifty feet ; certainly 

 not less. Its i^hysiognomy was rendered peculiar by a long projecting 

 muzzle, reminding one of that of the blunt-nosed sturgeon of our coast ; 

 but the resemblance was destroyed by the correspondingly massive end 

 of the branches of the lower jaw. Though clumsy in appearance, such 

 an arrangement must have been effective as a ram, and dangerous to 

 his enemies in case of collision. The writer once found the ^Yreck of 

 an individual of this species strewn around a sunny knoll beside a bluff', 

 and his conic snout pointing to the heavens formed a fitting monument, 

 as at once his favorite weapon, and the mark distinguishing all his 

 race. 



Very different was the Liodon dyspclor, a still larger animal than the 

 last, with a formidable armature. It Avas, indeed, the longest of known 

 reptiles, and i)robably equal to the great liuner-whales of modern 

 oceans. The circumstances attending the discovery of one of these 

 will always be a pleasant recollection to the writer. A part of the face, 



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