42 ANNALS OF THE QUEENSLAND MUSEUM. 
Upper profile of body rounded anteriorly, sharply ridged 
posteriorly, the sides rounded and inferiorly attenuated, so as to 
form an exceedingly fine cultrate cutting edge, its greatest width 
1*5 to 1*6 time the eye-diameter. Upper profile of head linear to 
above the eye, from whence there is a scarcely perceptible ascension 
to the suture of the first dorsal plate, beyond which the contour of 
the back is evenly and gently rounded to slightly behind the suture 
of the terminal plate, which is linear, with the extremity slightly 
bent downwards. Diameter of eye 2*1 to 24 in the postorbital 
portion of the head, and equal to or a little more than the inter- 
orbital region, which is strongly convex, and longitudinally striated, 
the striae originating from a low knob above the posterior border of 
the eye, from which also fan-like striae project over the temporal 
and occipital regions. Opercle tetragonal, as long as or a little 
longer than deep. Lateral plates mostly sculptured like the head, 
the three middle plates with the striae radiating from a central knob, 
those of the first interrupted by an oval pitted depression, thrice as 
long as wide, and rather longer than the pectoral fin ; those of the 
last longitudinally striated throughout nearly its entire length, the 
knob from which they radiate being situated near the suture ; this 
plate is also deeply grooved immediately below the dorsal ridge ; 
second and third lateral plates of equal width, twice as long as the 
first, the third narrower, 1*25 in the preceding plate ; second lateral 
plate as high as long, its lower edge much nearer to the ventral than 
to the dorsal profile, and almost wholly absorbed by a fan-shaped 
opaque area, which marks the position of the air-bladder ; sutures of 
all the plates smooth. Ventral plates 12, the first very small ; the 
second tetragonal with the anterior suture one third of the height 
of the posterior ; the third fan-shaped ; the fourth largest, with its 
upper border nearly twice as long as the lower, and having the pec- 
toral fin inserted in a depression, which occupies the postero- 
superior angle of the plate ; the fifth, sixth, and seventh about equals 
the others gradually decreasing in size to the last. 
Spinous dorsal with the first ray close to and parallel with the 
terminal spine, straight except at the extreme tip, which is slightly 
bent downwards and rather longer than the opercuio-pectoral inter- 
space ; second and third spines graduated and strongly curved 
throughout, the second produced beyond the membrane with the 
