3 
TI-DESCRIPTION OF THE GENERA AND STECIES. 
Telcostomi. 
CROSSOPTBRYGII. 
Suborder— AC TimSTf A . 
FantUij—C(EhkCKYiTm.'Qm. 
Genus non det. 
Plate II, Pig. 1. 
The ventral portion oi‘ the abdominal region of a Cadaeantli llsli of moderate 
size is the first and only evidenee of a C'rossopterygian hitherto discovered in 
the llawheshury-Wianamatta Series, One of the pectoral fins is well pre- 
served, and at a distanee of a1)out O’lT 1)ehind the insertion of this, there occur 
some fragmentary dermal rays evidently of a mneh smnller pelvic tin. No 
part of the squaniation of the trnnk, liowevei*, can l)e distingnished, and it is 
impossible to attempt even a generic determination of the specimen. 
The pectoral fin is preserved in counterpart, and the best impresshm is 
shown of the natural size in PI. II, Pig. 1. It cxhil)its, as usual, the charac- 
teristic obtuse lobation and the large fringe of articulated, attenuated dermal 
rays ; but the fossil is as yet iinicpic, so far as the Writer is aware, in displaying 
some of the endoshcletal supporting bones, Tliesc elements seem to bave 
been well ossified, though with persistent cartilage internally. At the base of 
the fin there occurs aii elongated broken fragment of bone, incapable of 
determination ; but in the lohe of the fin itself there is a scries of four well- 
defined hour-glass-shaped supports. Of these l)oncs the anterior three are 
much elongated and nearly equally slender, while the fourth is much more 
robust and widely expanded at the distal end. The four elements radiate 
from the anterior half of the base of the fin ; and it seems very prohable that 
some smaller cartilages behind and near the distal border of the lobe have 
disappeared from lack of ossification. The fin-rays gradually increase in 
lengfh from the anterior border to the middle of the lohe, whence they 
c 
