208 



THE EXTINCT BATRACIIIA, REPTILIA 



by a vertical depression; the posterior, or that meeting the odontoid process, is quite prominent and distinct. The 

 anterior facet for the occipital condyle, is transversely divided by a, depression. 



The form of the cervical vertebra is so much like that of the Mosasaurus deka.yi as to be readily taken for those of 

 small example of that species. The first, dorsals, or those without bypapophy sis, are more elongate than in the latter, 

 and the body is more cotractcd, so that the hall presents a, projecting rim all round. This is readily knocked off in 

 the rough handling the specimens usually receive. The cup is also proportionately expanded. Posterior dorsals 

 where the diapophyses issue half from the centrum, have the latter slightly depressed; -where the diapophysis comes 

 three-fourths from the body, the articular faces are a, broad transverse ovate, well expanded on the margins, below 

 which the surface is si iglitly striate. In the longer or anterior dorsals, the rudiment of zygosphen and y.ygantrum 

 is well marked. 



Unfortunately, no caudal vertebra) of this species hare been preserved, so that I do not know their form. The 

 posterior dorsals are so much more, depressed than in Liodon lsevis, that future discovery may justify the generic sep- 

 aration of the genus Nectoporthens, which I originally applied to this animal. 



For the largest measurements, I refer to Dr. Leidy's essay on Cretaceous Reptiles, where the description of the 

 large specimens of Macroaaurus lsevis belong to the present species. 



The following art; the proportions of the smaller and typical individual, from L. T. Germain: 



Inches. Lines. 



Length centrum cervical, (with ball) 34 



Depth ball of same, IN. 5 



Width " " 31. 



Length anterior dorsal, . 84 



Width cup, 24 



Proximal width outer face quadratum, 28 



Length quadratum to lower edge pit, 20 



" opisthotic, (see description) •! 4 



" outer margin do., 3 4 



This was a large and powerful reptile, and probably more elongate in proportion to its bulk than the Mosasauri, 

 well deserving the mime Mttcrosatinis which Owen has applied to an ally. 

 From the upper Green Sand Bed of the New Jersey Cretaceous. 



BAPTOSAUIIUS, Marsh. 



Proceed. Acad. Nat. Sci., Phila., January, 1870. Halisaurut, Marsh, Sill. Am. Join-. Sei. Arts, [869, 805 K nec 

 Johnsonii, 1S(i(>. 



A genus known chiefly from vertebrae. These resemble those of Liodon, more par- 

 ticularly such specie's as L. validus, but present marked differences in the cervical part, of 

 the series. Here the hypapophyses are compressed and elongate, and rugose at the ex- 

 tremity for the insertion of muscles, instead of being truncated by an articular lace to 

 which a separate bone is united, as occurs in all the other genera of Pythonomorpha here 

 enumerated. In this it moire nearly resembles the ordinary types of Lacertilia and 

 Ophidia. There is no indication of zygosphen in the two species described. The neural 

 spine is elevated, compressed, and narrow. The dorsals arc of an even more elongate 

 character than in liodon. The species known have the articular faces depressed or 

 transverse oval. This character is not necessarily of generic value, and hence I attach 

 less importance to it than does Marsh in his diagnosis. 



-<; 



