127 



group from which the latter have sprung. That this order is not that unknown 

 type is clear; but the indication of affinity to it is equally unmistakable. 



Restoration. 



The proportions and appearance of the Tythonomorpha can be determined 

 from the remains which have been procured. The body-cavity is more 

 elongate than in any group of lizards and saurians, excepting the Amphis- 

 btenia, but not so long as in serpents. The tail is excessively long and 

 flattened. The head is also long — in some genera, as Clidastes, very slender, 

 and always flat, with the eyes nearly vertical. There is no distinction between 

 neck and body, but a contraction behind the head. The limbs are very small 

 for the size of the animal, forming broad paddles, with but little peduncle; 

 the hinder limbs well behind the ribs, and often smaller than the anterior. 

 The general effect of the more slender of these animals was that of gigantic 

 eels, or some of the snakelike lizards of the present time, so that they are 

 veritable sea-serpents of the Cretaceous ocean, and would doubtless be 

 described as such were any perchance to be found to be still in existence in 

 the depths of modern oceans. 



Several peculiarities affecting the appearance of these animals may be 

 derived from the peculiar articulation of the lower jaws. The position 

 of these articulations in advance of the pharynx indicates a baggy extension 

 of the gular walls, to permit the passage of large bodies between the jaws to 

 the oesophagus. This had, perhaps, the appearance of the posterior part 

 of the pouch of the pelican. This arrangement necessarily requires that the 

 larynx should be, as in the serpents, in the middle or anterior part of the 

 mouth ; for, as in those animals, the delay involved in deglutition would cause 

 suffocation were the glottis immediately below the descending mass. This 

 structure requires auother, namely, the anterior position of the tongue ; and 

 this organ, unless very small, would have to be received into a sheath beneath 

 the larynx and opening anterior to it. Ensheathed tongues, among reptiles, 

 tend to become cylindric in proportion to the completeness of the sheathing, 

 for obvious mechanical reasons. It is almost certain that the Pytlionomorplta 

 had tongues of this kind; for their nearest living allies on both sides have 

 them, viz, the serpents and the varan ian or thecagloss lizards. These have 

 the tongue cylindric, ensheathed, and forked at the end, and project it as a 

 delicate tactile organ. 



