LARVAL AND POST-LARVAL FISHES—REGAN., 129 
Myctophum antareticum is very similar in form, proportions, position of the fins 
and number of rays, number of myotomes, ete., to the northern JL glaciale, Reinh., 
the principal differences between them residing in the number and arrangement of the 
photophores. Holt (P.Z.S. 1898, pp. 552-560, pls. XLVI, XLVI) has described young 
stages of the northern species, and it is interesting to note the resemblances and 
differences between these and corresponding stages of M. antarcticum. There is a 
general resemblance in the development of the two species, but MM. glaciale at 8 mm. 
long corresponds to M. antarcticum of 10 to 12 mm. and at 11°5 mm. to MM. antareticum 
of 16 to 18 mm., whilst at 14°5 mm. JL glaciale has the general characters of the adult 
fish, except that the eye, although considerably larger than in smaller examples, is not 
yet proportionately as large as in the adult. Post-larval examples of J glaciale differ 
from corresponding stages of MV. antarcticum in that they are not noticeably elongate 
in form as compared with the adult, the abdomen is prominent, the dorsal sinus extends 
from head to dorsal fin, and the latter is much higher than in Mf. antarcticum. 
Even if post-larval J. glaciale appear less elongate than the same stages of 
M. antarcticum to a great extent because the depth is increased by the large dorsal 
sinus and the protuberant abdomen, yet if these features be neglected, the southern 
species is at this early age noticeably more slender than the northern one. Jn both, the 
eyes at first grow at a slower rate than the fish as a whole, as is the rule in fishes 
generally, but later on grow faster than the rest of the fish, so that they are propor- 
tionately much larger in the adult than in the young. Holt’s explanation—that this 
is due to the fact that the adults live at greater depths than the young—may be 
unreservedly accepted. 
2. A NEW PARALIPARIS. 
Paraliparis terrae-novae, sp. n. (Pl. I, fig. 6). 
A young fish, 35 mm. long, was taken in McMurdo Sound on Jan. 16th, 1912, at 
Station 332, 77° 15'8., 166° 0’ E., 0-550 metres. It is very similar in most respects to 
P. antareticus, Regan, but differs notably in the fewer fin-rays (dorsal 55; anal 43) 
and in the form of the pectoral fin, which has no elongate lower rays. This is the 
second Antarctic species of this genus. 
3. THE NOTOTHENIJFORM FISHES. 
The “ Terra Nova” collection includes young stages of Pleuragramma, Pagetopsis 
and Chionodraco, from the Ross Sea and McMurdo Sound. As I have already made a 
systematic revision of the Nototheniiformes and have given a general account of their 
distribution, it seemed worth while to try and complete this work by describing the 
egos and young of the whole group, so far as possible, from the material in the British 
