Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/783

From Wikisource
Jump to navigation Jump to search
This page needs to be proofread.

longitudinal radiating striae. The upper extremity of some of the anterior spinous processes are strongly roughened at the sides, as if for muscular attachment.

The anterior zygapophyses are stout and well produced ; they inline outwards and upwards. The posterior pair are considerably shorter than the anterior, and stretch backwards or outwards to overlap them.

The transverse processes are not well preserved ; but distinct traces of them are observed in most of the vertebrae, and on one or two the form is pretty well seen. They are simple, short, and obtuse, and are lengthened a little in the direction of the long axis of the centrum.

The caudal vertebrae are longer in proportion to their height than those of the trunk ; and the neural arch, as in them, is completely united to the body, no suture or other trace of the junction of the parts being perceptible. The spinous process is as long proportionately, and those near the root of the tail are of the same shape as those of the trunk. But further down they become considerably contracted at the base in the direction of the long axis, and gradually widen in the same place upwards. The spine of the last joint on the slab, being the fifteenth or sixteenth of the tail, exhibits at the upper margin an indication of the peculiar bifurcation of the lower distal caudal spines of this saurian.

The anterior zygapophyses are considerably longer than those of the trunk-vertebrae, and are more inclined upwards. Immediately beneath the neural arch on either side of the centrum there is a longitudinal ridge, which, near the centre of the body, is produced a little into a short projecting tubercle, the transverse process. The chevron bones forming the haemal arch are about as long as the dorsal spine, but are much narrower, and are of a spatulate form, being narrower at the proximal and flat and small towards the outer extremity. They are not fixed, like the processes, in connexion with the neural arch, but are articulated below to the broad reflected margin of the posterior extremity of the body, articulated, as it were, between the joints, and are inclined backwards. Only a few of them remain, but two or three are well displayed on a fragment of the counter-slab, which has fortunately been preserved.

The lumbar vertebrae are not well marked, and in this region the specimen is unluckily fractured. Certainly two, perhaps three, of the last vertebrae of the trunk are, however, apparently anchylosed. Von Meyer seems to have been uncertain whether there were two or three pelvic joints ; but from what he states it would seem likely that three is the number.

A fragment of a flattened rounded bone, measuring 1-1/8 inch across, lies directly below the lumbar vertebrae. This is probably a portion of the pelvic girdle, and is the only indication of its presence. This resembles in form the rounded extremity of a bone (tab. iv. f. 1, 2, of von Meyer's work) lying in contact with the femur, and is probably a portion of either the pubis or ischium.

Immediately in front of the fragment lie the short ribs, which are