PALA ONTOLOGICAL MN@iies: 
Lysorophus tricarinatus—In 1877 Cope described from the 
Permian bone bed of eastern Illinois, three small vertebra which 
he referred to a new genus and species, Lysorophus tricarinatus. 
The specimens were later redescribed and figured by the author 
in the JOURNAL OF GEoLoey, Vol. VIII, p. 714, Plate I, Figs. 12a, 
126, 12e. This genus has not previously been recognized from 
any other locality, but in looking overa portion of the University 
of Chicago collection of Permian vertebrates from the Texas region 
I find the genus represented by some very interesting specimens. 
In a very restricted localityI found (the author collected the spe- 
cimens here described) several series of vertebre with attached 
ribs, which were peculiar inthat the animal was evidently closely 
coiled when fossilization took place. This is such a persistent 
feature that some trace of it is noticeable in even the shortest 
series of vertebrae. It is difficult to explain this feature; the late 
Dr. Baur, before the specimens were identified, suggested that they 
might be embryos, but this seems rather improbable from the 
persistence with which the vertebre cling together, and the very 
perfect degree of ossification. Another peculiarity is that the 
ribs are almost always attached but are crushed down and to the 
rear and are closely folded upon the vertebre. In Fig. 1, Plate 
I, is shown one of the series of vertebre with attached ribs, the 
curvature is not shown as it lies in the plane, perpendicular to 
the paper, but it is very noticeable in the specimen. 
In the type specimens only the centra were known, and the 
deep pits on the sides, with the sharp intervening keels were 
made the determining characters of the genus. In the specimens 
from Texas, the neural arches are still in position, but the line 
of suture is very distinct; in the few vertebre which have lost 
the neural arch, the characteristic angulation of the articular face 
of the centrum for the base of the neural arch, and the deep pit 
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