30 RAMSAY H. TRAQUAIR’S 
Rhadinchthys Macconochii, sp. nov. Traquair. 
Pl. IT. figs. 12-16. 
Description.—Length from 3 to 34 mches; shape elegantly fusiform, the 
dorsal and ventral lines being gently and evenly curved. The length of the 
head is contained a little more than four times on the total, and is equal to the 
depth of the body midway between the pectoral and ventral fins. 
The cranial roof bones are ornamented with a close, comparatively coarse, 
and frequently confluent tuberculation ; the orbit is, as usual, anteriorly placed, 
and the ethmoid forms a projection over the mouth. The suspensorium is 
very oblique, and the gape correspondingly extensive. The maxilla is of the 
usual form, its broad portion being ornamented with closely set ridges, which 
run parallel with its superior and posterior margins; the beautifully tapering 
mandible is marked externally with ridges which pass from behind forwards in 
a slightly radiating manner, but which are also so frequently interrupted as to 
cause the ornament to assume nearly as much of a tuberculated as of a striated 
aspect. The operculum is of moderate size, rather broader below than above ; 
the interoperculum is rather large; both of these plates are ornamented with 
prominent and proportionally coarse ruge, which run mostly parallel with the 
lines of growth. 
The bones of the shoulder girdle present nothing peculiar in form and 
arrangement, and are sculptured externally with ridges similar to those on the 
opercular bones. 
The scales are of medium size, rhomboidal, as usual diminishing im size 
dorsally, ventrally, and posteriorly ; they are low and narrow on the belly from 
the throat to the anal fin, while those of the front part of the lateral line are 
proportionally higher than the others. The scales of the middle line of the 
back are small until just in front of the dorsal fin, where a few of comparatively 
large size and imbricating arrangement are found. Im one specimen 45 
oblique dorso-ventral bands of scales may be counted from the shoulder 
girdle to the commencement of the lower lobe of the caudal fin. The scale 
ornament is sharpest on the scales above the lateral line, where it consists first 
of a few sharp grooves parallel with the anterior margin, and tending below to 
turn round along the inferior one, the rest of the area being occupied by two or 
three slightly prominent ridges, passing somewhat obliquely across towards 
the posterior margin, before reaching which they usually stop short, a pro- 
minent feature in this species being that on no part of the body do the scales 
appear to be denticulated posteriorly. Towards the tail the vertical furrows 
become imperceptible, or reduced to a single one. Below the lateral line the 
scale ornament is for the most part less marked, though similar in character, 
but towards the tail pedicle little or no difference is seen above and below. 
