AND AYES OF NORTH AMERICA. 



207 



Depth ball, 



Width " 

 " cup, 



Depth " 



Length base neurapophysis, 

 In profile the base has a. vei y slight obliquity looking upwards. 

 From the Rotten Limestome of Alabama; discovered by E. R. Showalter, M. I). 



Linen. 

 10.4 

 11 



12.(5 

 11. 

 12. 



LIODON VALIDUS, Cope. 



Maerosawus validus, Cope, Proc. "Boston, 1860. Neotoportheus validus, Cope, Proo. A. N. Soi., PhU. 1808, p. 181. 

 Leidy, Cretao. Kept. 74-75; Tab. VII, li), 20, III 1-2. 



This species is represented by two cervical and four dorsal vertebra of one individual, and a, large dorsal of another, 

 in the Museum of Hie Academy; the former associated with numerous fragments, including part of an OS quad- 

 ratum, from L. 'P. Germain, Burlington Co., N. .1. Two dorsal vertebra of a large individual in the Museum of Rut- 

 ger's College, submitted to me by Prof. Cook; several vertebra with broken quadrate and Other bones and teeth, in my 



private collection, from near Barnesboro, Gloucester Co., N. .1.; a, similar series with portions of the cranium from the 

 same locality, in Cabinet of N. .1. State Geol. Survey, and a number of vertebral in the collection of Prof. Marsh, of 

 Yale College, further establish its characters. 



The quadrate hone, is highly peculiar', as above pointed out. The posterior descending hook of the proximal ex- 

 tremity is quite short, and is marked by an obtuse ridge which passes forwards and disappears immediately above the 

 pit alongside; the meatus. What especially characterizes this species and genus, and allies it to Clidastes, is the pres- 

 ence of a strong longitudinal angular ridge, which extends from the usual external angle of the proximal extremity, 

 which becomes here a, process, separating the Outer aspect of the quadiafum into two entirely distinct planes; one that 

 of the meatus, the other that of the ala. 



Two separate opisthotic bones accompany these remains, which were mixed up with those of the M. depressus. The 

 vertebra; of the two species wore easily separated. The quadrate bone also was identified by one accompanying the 

 vertebra; of M. validus in my own collection. I could not so readily assign the opistboties to the proper species. I 

 have assigned them here, because their glenoid cavities apply much more readily to the quadrate bone of the M. 

 validus than of the M. depressus. As compared with the same bones of three Mosasaurus dekayi, they present three 

 marked characteristics. First, they are relatively much shorter; second, the distal anterior process which fits within 

 the squamosal, is much more prolonged; third, the inferior of the two laces to which the squamosa] is applied, is a 

 continuation of the; general Inferior plane of the bone; in M. mitchillii it is a different plane, like a, rabbet. It may 

 be added, that tin; glenoid cavity is narrower and deeper. 



Fowr teeth from liaincshoio, indicate marked characters. They are much compressed, as in L. mitchillii, and the 

 posterior cutting edge is well developed and forms the narrowed extremity of an elliptic section. The anterior ridge 

 less developed. In three crowns there is no trace of the unequal division by these edges, as in Mosasaurus sp. One 

 probably from the premaxilla is more abruptly recurved than in the others, with base rather expanded inwards. The 

 distinguishing character of these; teeth, which separates it- from L. mitchillii, is the abundant longitudinal fluting and 

 striation of the enamel. The grooves are deeper and shallower, coarser at the base; the strise are fine, continuous and 

 rugose. These are not seen in L. mitchillii. The general form of the crown is short, broad at the base and well 



curved posteriorly and inwards. 



Linen . 

 21 



1(5 

 12 



Elevation of crown and pedestal, 



" " alone, 



Antero-postcrior diameter do. at base, 



The lateral clement of the atlas is represented from the inner side in Fig. 48, No. :S. The anterior termination 

 of the inferior ala, and the articular face for the centrum, are as in M. mitchillii. The inner articular face is divided 



