DEVELOPMENT AND LIFE-HISTORIES OF TELEOSTEAN FISHES. 809 
During the following days the black pigment continues to increase, especially at the 
base of the abdomen. At first the radiate corpuscles are separate, but they subsequently 
anastomose and form dense patches. 
16th day (Pl. X. fig. 2)—The great size of the pectoral fins (pf) is the most 
prominent feature at this stage. They are in constant motion, flapping to and fro like a 
pair of fans, and the pigment (pt) on their surface is largely developed. The yellowish 
yolk has shrunk very much, and forms an irregular mass in the pectoral region, the oil- 
globule, apparently undiminished in size, still occupying a posterior position. A large 
vacant space (ss) is left in front of the rectal tract, and a similar large space (ss) occurs in 
front of the yolk. The snout is much elongated, and viewed from above is like a 
truncated cone just as in the adult gurnard. A feature of moment is the comparatively 
motionless condition of the mandible (mn). The marginal fin (ef) shows no differentia- 
tion into definite fin-areas; it is, as compared with the breadth of the body, now 
proportionately narrower. As above noted, the pectorals (pf, Pl. X. fig. 2a) are the 
most noteworthy feature, standing out almost at right angles to the trunk, and so well 
developed that, viewed obliquely, the young fish resembles very strikingly Pegasus natans. 
Under a lens the yellowish pigment is seen to be confined chiefly to the head, pectorals, 
and yolk-area. A few corpuscles occur along the margin of the dorsal fin in front, and 
a few also on the tail; but the body has fewer of them than previously, finely branched 
black corpuscles alone being present. A later stage (Pl. X. fig. 3), about three weeks 
after emerging from the egg, exhibits much the same features—a chitinous bar being 
prominent in the premaxillary region. The next stage under observation was procured, 
along with a large number of others, while in the Fishery Board tender “ Garland,” and 

the specimens were slightly larger than the last stage described, viz., about 6 mm. in 
length. They clearly were the young of the same year, as they were obtained at the close 
of summer, viz., 3lst August. The great size of the head generally, as well as of the 
eyes and brain, was characteristic, and especially the broad scoop-shaped snout with the 
median “bite.” Behind the head the pendulous abdomen projected like the yolk-sac 
(now almost wholly absorbed) of the earlier stages. The stomach, in fact, was found to be 
greatly distended with minute Copepoda, which form the staple food at this time. The 
pectorals are even larger than in the previous stage; while the marginal fin with its 
embryonic rays continues into the tail fin, which shows the notochord as a median 
slightly tapered axis. From this axis the rays below slant downward and backward, 
while those above lean upward and backward. Those coming from the tip of the 
notochord are short. The ventral rays are larger, and a granular opaque tract below the 
chorda probably indicates the site of the future hypurals. No cartilagmous rays are 
present. The marked downward projection of the angle of the jaw, and the lean tapering 
body behind the massive abdominal region are noteworthy features. As the specimens, 
on account of their extreme delicacy, were injured by the pressure of the water against the 
net, it was necessary at once to consign them to alcohol, and their colours were thus 
more or less lost. Large stellate pigment-spots could, however, be distinguished along 
VOL. XXXV. PART III. (No, 19). oi 
