386 Prof. O. C. Marsh—New Jurassic Dinosaur. 
chord, indicate a stupid, slow-moving reptile. The beast was wholly 
without offensive or defensive weapons, or dermal armature. 
In habits, Brontosaurus was more or less amphibious, and its food 
was probably aquatic plants or other succulent vegetation. The 
remains are usually found in localities where the animuls had 
evidently become mired. 
Among the new points in the skull of the Sauropoda recently 
determined are the following :— 
Pituitary Fossa.—In Morosaurus, the pituitary fossa is compara- 
tively shallow, much like that in the crocodile, and many birds, 
being connected with the under surface of the skull by the two usual 
divergent foramina for the passage of the internal carotid arteries. 
In Apatosaurus, however, it is remarkably different. Here the fossa 
becomes enlarged into a vertical canal, which, expanding below, 
communicates by a wide transverse orifice with the pharyngeal 
cavity. The arterial foramina are here canals thinly covered over 
with bone, and open just within the rim of the lower orifice. The 
pituitary cavity itself has a firm smooth wall throughout. The 
openings are both transverse, and oval in shape. The upper one is 
eighteen by six millimétres in its diameters; the lower opening 
thirty by twelve. | 
This remarkable connection of the cerebral cavity with the alimen- 
tary canal is an embryonic character, and corresponds to the con- 
dition observed in the chick at the fifth day of incubation. This 
peculiar feature appears to be a family character of the Atlantosau-~ 
ride. 
Post-occipital Bones.—In two genera of the Sauropoda (Moro- 
saurus and Brontosaurus), and probably in all members of this order, 
there is a pair of small bones connected with the skull which have 
not hitherto been observed in any vertebrates. These bones, which 
may be called the post-oecipital bones, were found in position in one 
specimen, and with the skull in several others. When in place, they 
are attached to the occiput just above the foramen magnum, and 
extend backward and outward, overlapping the lateral pieces of the 
atlas, thus protecting the spinal cord at this point, which would 
otherwise be much exposed. 
These bones are short, flattened, and slightly curved, resembling 
somewhat a riblet. The anterior end is thickened and rugose for 
attachment to a roughened surface on the exoccipital, just above 
and outside the foramen magnum. The shaft is flattened from 
above downward, and gradually converges to a thin posterior end. 
In Morosaurus grandis, these bones are about 65 mm. in length, and 30 
along the surface which joins the occiput. They correspond in position 
to the muscle in mammals known as the rectus capitis posticus minor. 
In the existing Cormorants (Graculus) a single slender bone is 
articulated to the occiput on the median line. This, however, does 
not correspond to the bones here described. To distinguish it from 
the post-occipitals, it may be called the nuchal bone. 
Stapes wanting.—In the skull of Morosaurus in which the post- 
occipital bones were found in position and the other bones at the 
