282 
Cope.] [Dee. 17, 
regions. The ball of the axis is round, those of the vertebrae early suc- 
ceeding are moderately depressed. The balls of the dorsals are transverse 
elliptic with a slight concavity for the neural canal ; the plane a little ob- 
lique to that of the long axis, The centra are more depressed posteriorly 
where the balls of the dorsals present rounded lateral angles. On the lum- 
bars preceding the caudals, the base of the neural canal becomes more 
elevated, and the articular faces assume a slightly pentagonal outline. 
This form continues as far as our specimens of caudals extend. On three 
lumbars, the centra present two longitudinal angular ridges below, at 
whose posterior ends the chevron articular surfaces appear on the first 
caudals, All present an incised marginal groove to the ball. The sur- 
face, especially the inferior, is strongly rugose up to this groove, espe- 
cially on the dorsals. 
The aais is much shorter than in any other species here noted, where 
known. The neural spine has a very oblique superior margin and is ex- 
panded behind. The diapophyses are narrow, and continued as vertical 
plates to the inferior face of the centrum at its anterior margin. The 
diapophyses of the other cervicals have the usual horizontal limb, which 
is, however, shorter than the vertical. In the anterior dorsals, they are 
directed more obliquely upwards and are longer. These, and all other 
dorsals, maintain a connection between the rim of the cup, and the 
anterior basis of the diapophysis by a smooth area apparently capped 
by cartilage in life, as exists in L. cwrtirostris. As we pass posteriorly 
these processes descend, and become narrower, until finally they thin out 
and lengthen into the ribless diapophysis of the lumbars. Those of the 
caudals are long and subcylindric. Their extremities are deeply striate 
grooved. The neural spines of all the vertebre are longitudinaly striate 
keeled, The zygapophyses are remarkable for their narrow form and 
surfaces. The atlas is shorter on the outer, and longer on the inner face 
than in L. validus. This is caused by the fact that the posterior articu- 
lar face is not transverse, but very oblique, and instead of being vertical 
and narrow, is obliquely longitudinal in its long axis. It is separated 
from the inner face by a wide rugose groove behind ; its lower edge sends 
a keel downwards. There is no process at the thinned infero-anterior 
angle. 
The scapular arch was small especially the scapula, which is absolutely 
smaller than that of the Holcodus tetericus, a very much smaller reptile. 
The posterior margin is thickened, the anterior thinner, and less elevated. 
The superior is arched upwards and backwards. The general form is less 
oblique than in Z. detericus. The coracoid is twice as large, and is flat 
and thin. Its inner margin is regularly convex, the posterior concave 
and thin, the anterior thickened. The foramen is present. 
The humerus is different in form from that observed in LZ. erassartus, L- 
ictertous, Clidastes, etc. It is relatively less expanded proximally and 
especially distally ; there is but one deltoid crest, which is proximal and 
near one extremity of the articular surface, and disappears into the gene- 
