1878.]; 519 (Cope. 
Measurements. M. 
Length of a centrum with an intercentrum attached.... .0056 
Length of centrum............ bhaiste ebstats staletaretetsietars tess . -0040 
Dinwmeten of centaam vertical. MW cecepakel Telstar stele Stare oe is -0035 
HOVIZONtaleyace rsh este chetels s sta mpoceesO03D 
Expanse of diapophyses......... epee sycialersverssakevenas aiais 270 -0080 
heads} Ot) wiley. poses Yonrs mieindetee darts 0085 
Elevation to summit of neural canal..... afstd datat etal ever . -0045 
Comparison with the vertebrae which I have found associated with the 
jaws and teeth of Bolosuurus striatus reveals the following differences : 
The neural arches of the latter are distinct ; the intercentra are not present 
on the vertebrie observed (five in one series and five in another) ; and the 
centra are compressed with inferior rib. There are no capitular articular 
facets in the vertebre of Bolosaurus described. 
THEROPLEURA RETROVERSA. Gen. et spec. nov. 
Char. Gen. Rhynchocephalian reptiles with free neural arch, and a 
capitular costal articulation on the centrum ; the intercentrum probably, 
and the hyposphen certainly, wanting. 
This genus is similar to Lysorophus in its free neural arch, but there is 
no capitular costal articulation on the known vertebre of that genus. The 
small costal face of the diapophyses is distinct from what is seen in Hpicor- 
dylus and Hmpedocles. 
Char. Specif. Size medium, or rather larger than that of Clepsydrops 
natalis. A number of small vertebre may belong to a young individual, 
but I regard as type a dorsal vertebra of an adult, where the suture of the 
neural arch is visible but adherent. The species is characterized by the 
wide posterior expansion of the border of the articular face of the centrum, 
forming the capitular facet for the rib. It approaches near to the dia- 
pophysis, and descends to the basal fourth of the centrum. There is an 
angular ridge passing backwards from the inferior border of the diapophy- 
sis to the border of the articular face. Below this angle and behind the 
eapitular costal face the centrum is deeply concave, the concavities of the 
opposite sides being separated below on the median line by a narrow ob- 
tuse keel. The centrum is as deep and long as wide. 
Measurements. M. 
AMLELO-POSTCLIOLs late <eierele eteteres eo 
Diameter of centrum ~ vertical............... aalaiele sree: UO 
UTANISVIETSCLS retee a alas Sivernte stds ators .025 
The small specimens agree with the large one in the strong, longitudinal 
angle connecting the diapophysis with the posterior border of the centrum, 
and in the wide capitular articular surface. 
THEROPLEURA UNIFORMIS. Sp. nov. 
This species is represented by the vertebrae of two individuals, and per- 
haps of two others of smaller size. The dorsal centra are characterized by 
* Proceedings Amer. Philos. Soc., 1877, p. 187. 
