1869.] 257 [Cope. 



developed; they resemble those of some saurians. These eliements 

 do not exist in the Ophidia, where hypapophyses take their place. 

 A structure somewhat resembling the latter seems to exist in Elasmo- 

 saurus. 



The parietal fontanelle is similar to that seen in Lacertilia and 

 Sauropterygia. 



Thus seven characters in which it resembles the Lacertilia are shared 

 by at least one other order of reptiles. In its lacertilian characters 

 it approaches nearest the Varanidae, which themselves, offer some 

 approximations to the Ophidia. The elongation of the prootic ante- 

 rior to the internal ear is a character of all the slender-tongued 

 lizards, and the long superior nostrils and lack of malar arch belong 

 only to the Varani. 



The singular manner in which the opisthotic is supported is only 

 paralleled, so far as I am aware, by the ophidian family of the Tor- 

 tricidae, where it is similarly projected from the grasp of the prootic 

 and exoccipital, as suspensor of the quadratum. In Cylindrophis the 

 parietal and part of the supraoccipital enter the connection also. 



The anterior limbs, as has been observed, combine the characters 

 of Testudinata and Sauropterygia. The ulna and radius, and all 

 more distal portions of the limbs, are those of the latter order. The 

 large, ovoid, flat carpals, and flat, medially contracted digits, with 

 fixed articulations, are of that type. 



From the preceding evidence, we may now look upon the mosa- 

 sauroids and their allies as a race of gigantic, marine, serijent-like 

 reptiles, with powers of swimming and running, like the modern 

 Ophidia. Adding a pair of short anterior paddles, they are not 

 badly represented by old Pontoppidan's figure of the sea serpent. 



That terrestrial representatives now unknown to us, inhabited the 

 forests and swamps of the Mesozoic continents, and strove for mastery 

 with the huge dinosaurs, that also sought their shades, is probable. 

 That their habit was to devour whole is evident, and though the 

 articulation of the lower jaw will not admit of as much extension as 

 that of the Ophidia, it exceeds other reptiles in this capacity in con- 

 sequence of the lateral motion of the splenial articulation. The 

 carnivorous dinosaur, on the other hand, tore his prey to pieces, as 

 do mammals of the present day. 



Thus in the mosasauroids, we almost realize the fictions of snake- 

 like dragons and sea serpents, in which men have been ever prone to 



PBOCEEDIXGS B. B. N. H.— VOL 511. 17 MARCH, 1868. 



