1883.] Zoology. 1181 
deeper into the sea, and, indeed, from the analogy of Torel’s in- 
vestigations in the Lake of Geneva, as far as 100-200 fathoms. 
Now, it is certainly very remarkable that the limit of nullipore 
plants occurs at 150 fathoms, and A. Agassiz cites precisely the 
same limit for the greater part of those littoral animals which ex- 
tend beyond their normal boundary for some distance into the 
region of the deep-sea fauna. 
Many deep-sea animals, living in darkness, either have un- 
commonly large eyes, like nocturnal animals, or are completely 
blind. It is also well known that they are, for the most part, 
either pale and colorless or unicolorous, and that varied colora- 
tion is exceedingly rare, while a large proportion are luminous. 
This last peculiarity the writer thinks of special importance, for 
itis clear that luminosity can be of consequence only to such 
animals as are destined to live in darkness. 
He also refers to the fact noticed, by Moseley and others, that 
the pelagic fauna shows a very great resemblance to the deep-sea 
fauna. It is well-known that by far the greater part of the pel- 
agic animals are animals of darkness, dwelling during the day in 
the obscure depths of the sea, and only coming to the surface at 
ran Luminosity is also as common among pelagic as deep-sea 
animals, 
; . Now 5 
two blind Ophidiidæ, showing the closest resemblance to their 
relations of the deep sea, are found in the caves of Cuba.” 
n conclusion, Fuchs refers to the geological bearings of the 
Subject. He had previously shown that, during the geological 
Periods, when a warmer climate than at present prevailed at the 
fi logical epochs, and in general we should lose all reliable 
for judging of the faunistic conditions of geolo 
