MANSFIELD DISTRICT, VICTORIA. 
Fig. 2. — Ditto ; impression of part of abdominal region, showing 
mould of pelvic fin-spines, incomplete behind 
{a, a), part of both pectoral fin-spines ( b , b), 
and some dermal tubercles (c); nat. size. 
2a. — Cross-section of mould of pectoral fin-spine just 
beyond the hinder end of its inserted portion, with 
matrix occupying position of the groove on its 
narrow posterior face ; nat. size. 
2b. — Similar cross-section near hinder end of pelvic 
fin-spine, showing its slight compression and an 
indication of the postero-internal groove; nat. size. 
2c. — Diagram of outer aspect of dermal tubercles with 
rounded bosses ; five times nat. size. 
2d . — Diagram of tuberculated ridges of paired fin-spine; 
magnified (not satisfactory, the intervening grooves 
scarcely wide enough). 
2c. — Cross-section like 2a, but near the anterior end of 
the pectoral fin-spine ; nat. size. 
Plate III. 
pig. i. — Gyracanthides murrayi , sp. nov.; portion of abdominal 
region showing remains of pectoral fin-spines with 
their slender distal end appearing vaguely through 
the hard matrix; numerous dermal tubercles (a); 
the pelvic fin-spines, evidently approximated by 
crushing, in part preserved, in part as impressions 
of the outer face ( b ) ; and a trace of the plate at 
the base of the posterior free pectoral spine (c); 
nat. size. 
la. — Gutta-percha impression of the same specimen, 
showing the rounded shape and characteristic 
ornament of the bases of the pelvic fin-spines ; 
nat. size. 
1&. Longitudinal broken section of the pectoral fin- 
spine of the same specimen, showing its fibrous 
structure; nat. size. 
[ 27 ] 
4a 
