30 
ACTIXOPTERYGII. 
few of these arches are shown of the natural size in 
PI. I. fig. 4. Egerton Coll. 
P. 3362. Imperfect head, pectoral arch with fins, and some of the 
anterior vertebral arches, described and figured by Eger¬ 
ton, loc. cit. p. 873, pi. lxix. The portion of axial 
skeleton behind the head is not accurately drawn, there 
being only a single series of long slender spines loosely 
apposed to their more robust neural arches. As remarked 
by Traquair, the maxilla is interpreted by Egerton as 
mandible (numbered 32), the palatine (or ectopterygoid) 
as maxilla (21), the suborbital as premaxilla (22), and the 
jugal as coalesced mesotympanic and hypotympanic (28 d). 
Enniskillen Coll. 
Pig. 5. 
Head of Chondrosieus acipenseroides, seen obliquely from below (after 
Traquair). [No. P. 2048.] 
Lettering of figs. 5 and 6:— 
ag., angular ; hr., branchiostegal rays; ch., cerato-brancliial; c.h., cerato-hyal; 
cl., clavicle ; cl., dentary; f., frontal; hm., hyomandibular ; rn.pt., mesopterygoid ; 
rnx., maxilla ; op., operculum ; pa.sph., parasplienoid ; pt., palatine ; pt.f, 
post-frontal; s.cl., supraclavicle; s.o., suborbital; s.op., suboperculum; sq., 
squamosal. 
