230 



TIIK EXTINCT BATRACHIA, REPTILIA 



APPENDIX TO THE REPTILIA. 



CROCODILIA, 



Botlosaurus, Agass. 



Bottosaurus tuberculatum, Cope, Sp. nov. 



From an examination of additional material, I am disposed to believe that the Bottosaurus, described under the 

 head of B. harlani, at page (!•">, as a smaller individual, really represents a different species which I name above. The 

 material is from the same locality as the above specimen, and consists of twenty-seven vertebras from the dorsal, lum- 

 bar, sacral and caudal series, with large portions of the pelvis and both hind limbs, including two perfect femora; 

 also, about fifty dermal bones. 



Cranium and teeth. These are described as above. The acute, conic dental crown, which, I at one time referred 

 to the position of canine of B. harlani, I believe to indicate the specilic distinctness of the present animal. The 

 specimen of the latter appears to be mature, as one half the neural arches of the vertebra.; are coiissilied; the size is, 

 therefore, not more than half that of B. harlani. 



Vertebra'. A prominent character to be noticed is that none of the dorsal and lumbar series has compressed 

 centrum, as is the case with most of the Holopes; nor have any of the posterior dorsals the compression seen in H. 

 ohscurus. Second, the centra, never present the parallelogranrmic horizontal section seen in the 1 lolopos; on the contrary, 

 they are much contracted just in front of the articular ball, and flare out regularly laterally, to the rim of the sooket. 

 The lip of the cup is thin, and the cup inclines to narrow downward, especially anteriorly. This is owing to the fact that 

 the inferior median line becomes pinched or narrowed on approaching the position of the hypapophysis. One verte- 

 bra with the latter is preserved; the process is broken off, but had a small basis. 



Width enp first lumbar, 

 Depth " " 



Length centrum, 



Linen. Lines. 



21.2 Width neural canal, 7.4 



17 Anteroposterior length between ends of 



2S.fi zygapophyses, ?A 



Expanse of anterior pair of do., 45 



Width cup (ifl,li dorsal, 20. 



Depth " " 16.0 



Length centrum do., 27 



Width neural canal 6.8 



Antero-posterior spread of zygapophyses, 88.4 

 Expanse of anterior do., S58.2 



The Femora are large in proportion to the size of the verfebne. The head exhibits the round form characteristic of 

 Ilolops, and not the obliquity of Eyposaurus. What characterizes if is flic, great prominence of the ridge, rudimental 

 in the hitter, which represents the third trochanter of Dinosaurla. This prominence is increased by flic, presence both 

 anteriorly and posteriorly of a strongly marked pit. Another marked characteristic, not seen in other genera, is flic 

 truncation of the posterior margin of the shaft close to the head, down to nearly opposite the third trochanter; flu; 



surface thus produced is deeply grooved. Inside of the head roughly grooved; outside flatter, more finely grooved; 

 a grooved swell, in the position of flic great trochanter of other forms. The shaft, compared with the Holopes and 

 llyposaurus, figured in the present work (PI. IV.,) is shorter and more curved. The condyles are wide, with narrow 

 posterior prolongations extending on each side of a wide and deep popliteal groove. 



Length of right lemur, 



Width head, 



Length to 3d trochanter, 



The tibia is stout and slightly curved; the condyloid extremity presents two articular surfaces at right angles to 

 one another, of which the longer is contracted in respect to the length of the bone, and is supported by a, thin mar- 

 gin. The proximal extremity is broken from that of one side, but remains with a, part of the shaft of the other. 



In. 



Lin. 





In. 



IAn. 



10 



8 



Expanse condyles. 



2 



HA) 



2 



0.8 



Circumference shaft at 







:s 



11-7 



middle, 



4 



4. 



