A NEW FOSSIL REPTILE. 1005 
The palate of Broomia is not very unlike that of Varanosaurus, 
but differs in the wide basisphenoid, the very large inter- 
pterygoidal vacuity, and the more abundant teeth. ‘The lower 
jaw of Broomia is quite distinct from that of any Therapsid in 
that it has a boat-shaped angular in place of the characteristic 
flat-notched angular of the Therapsid. The vertebral column is 
also somewhat similar to that of a Poliosaurian, but the neural 
arches are heavier and the rib articulations not so wide. The 
shoulder-girdle differs in that the shoulder-girdle of the Therapsids 
always has a posterior coracoidal element which may be only 
cartilaginous but contributes to the glenoid cavity. 
The dium of Lroomia is strikingly like that of Pacilospen- 
dylus, and not unlike that of Varanosaurus. The foot resembles 
in some ways that of Varanosaywrus and is almost identical 
with that of Ophiacodon, which P.iof. Williston believes to belong 
to that group. 
The difference in the lower jaws shows at once that Broomia 
does not belong to the Therapsid line, and the resemblances 
between Varanosaurus and Ophiacodon and Broomia seem to be 
in general either primitive features or adaptive ones. 
ft have compared roomia with Casea but see no special 
resemblance between them. (Casea is perhaps an extremely 
early offshoot from the Therapsid stock before it had acquired its 
characteristic angular.) 
Broonia has an obvious superficial resemblance to Arwoscelis 
in that they are both very lightly built reptiles of small size. It 
is at present difficult to compare them in detail. From the 
published accounts of W illiston I have been able to find the 
following resemblances :— 
In both there are teeth on all the bones of the palate. If 
Broom’s Ophiodewus, founded on the specimens of ‘ Bolosawrus” 
figured by Case, is really Arwoscelis, then there 1s a very striking 
sunilarity in the palate of the two types, in the large inter- 
pterygoidal space, very long parasphenoid, and general structure. 
The dorsal vertebre are similar in their slender notochordal 
centra and heavy arches. The ribs are similar in having only a 
single slightly expanded head which articulates with the arch 
and centrum near the front end of the vertebra throughout the 
series. The sacrum of dArwoscelis is said to be almost indistin- 
guishable from that of lizards; that of Lroomia also resembles the 
same forms. The tail is long in both types. 
IT can find no characters in which the incompletely known 
humerus of Broomia differs from that of Arwoscelis. The femur 
and tibia of the two types seem to agree. 
The more important known differences between the two types 
are that Arwoscelis retains the primitive two coracoidal elements 
and that there is no trace in that type of the cut-away side of 
the skull of Broomia. At the same time it must be remembered 
that the facts are not certainly known in our fossil and that the 
jugals of the two forms have a considerable resemblance. 
