148 “TERRA NOVA” EXPEDITION. 
ACERATIIDAE. 
Haplophryne mollis, Brauer (Pl. X, fig. 2). 
A specimen of 10 mm. is very similar in outline to the one figured by Brauer 
(Valdivia Tiefsee Fische, pl. XVI, fig. 10); but this outline is that of the loose skin in 
which the fish is enclosed, and that of the body of the fish is quite different. The dorsal 
and anal rays are long, but only their tips project, and a rudiment of the illicium 
is present, but is hidden under the skin. 
Station 127. Off Three Kings Islands. Surface. August 25th, 1911. 
IIl—NOTES AND CONCLUSIONS. 
1. PELAGIC LARVAE IN RELATION TO THE DISTRIBUTION OF SPECIES. 
The larval, post-larval, and young fishes of the ‘“‘ Terra Nova” collection were all 
taken at or near the surface. The majority of those captured far from land, whether 
in the Antaretic (Notolepis coatsii), Subantarctic (Myctophum antarcticum), South 
Temperate or Tropical Zones (cf. p. 134) belong to oceanic species, either pelagic or 
bathypelagic. On the other hand, most of those taken near the coast are young 
stages of coast fishes which, when adult, may either swim near the surface (e.g, 
Clupeidae) or live at the bottom (e.g., Heterosomata). This is in agreement with the 
fact that the same species of coast fishes rarely inhabits areas separated by a wide 
expanse of sea; for example, the majority of the Brazilian species are not found on 
the West African coast. It may be inferred that the distribution of a benthic species 
along a coast may be helped by a pelagic larval phase, but that unless this be 
prolonged it will not serve to establish the species in places separated from its 
original habitat by a wide sea. 
Bothus ocellatus (p. 147), one of the Flat-fishes, is a good example of a benthic 
fish with a prolonged pelagic larval phase. The ‘“ Terra Nova” example, more than 
an inch long, is still transparent and symmetrical; it was taken in the Atlantic 
in 5° §., 27° 15’ W., quite 300 miles from the American coast. Jordan and Evermann 
give the habitat of this species as from “Long Island to Rio Janeiro, on sandy 
shores” ; but a specimen in the British Museum collection proves that it also occurs 
at Ascension, about 1,000 miles from Brazil. There can be little doubt that it has 
reached this island owing to the long duration of its life as a pelagic larva. 
The Eels, Apodes (p. 140, Pl. VII, figs. 5-7) are benthic fishes with pelagic larvae 
that attain a considerable size and age and may migrate for long distances ; but the 
majority of the Atlantic species of this group are not common to the eastern and 
western coasts. 
There is considerable evidence that some coast fishes with a wide geographical 
ee 
