Botany and- Zoology. 423 



in all my experience of surface collecting I have never met with 

 such prodigious masses of surface pelagic animals as on the hot- 

 test days of our dredging expeditions. When the sea happened 

 to be smooth as glass under a blazing tropical sun it seemed as 

 if the water was nearly solid as far as the eye could reach with 

 countless surface animals of all sorts. It is true that such re- 

 markable collections were only seen in the track of the Gulf 

 Stream when at a distance from shore, or when we were in the 

 track of currents due to the influence of neighboring islands or conti- 

 nents. 



We have "a considerable number of deep-sea sedentary types 

 which have an extraordinary bathymetrical range. There is no 

 reason therefore why pelagic animals which are more or less help- 

 less and drift at the mercy of the waves and winds and currents, 

 should not be able to flourish under similar extremes of pressure 

 and temperature. The more so as the majority belong to groups 

 of Invertebrates, on which the effects of pressure Mould be far 

 less perceptible. The tow-net trawling of Murray in some of 

 the deeper lochs of the western part of Scotland indicates that 

 the range of this deep-sea pelagic fauna does not extend far from 

 the bottom, although specimens of nearly all the species occasion- 

 ally find their way to the surface. There is nothing to show that 

 the more active deep-sea Crustacea, Fishes, Cephalopocls, Ptero- 

 pods, Annelids, Acalephs, Polyps, Rhizopods have not a con- 

 siderable range and may pass rapidly either vertically or near 

 the bottom through layers of water of very considerable differ- 

 ences of temperature and pressure. That this movement takes 

 place through all intermediate layei'S of water near the shores 

 within moderate depths seems conclusively proved by Chun's 

 investigations. That it takes place far from the continental 

 slopes in the oceanic areas is altogether another question. Chun 

 has also come to the conclusion that the surface pelagic fauna 

 does not extend to any great depth, but he has undoubtedly 

 shown that within a short distance from the shore there are a 

 large number of deep-sea pelagic animals living within a moderate 

 range from the bottom, and that they occasionally come to the 

 surface. These deep-sea pelagic types become mixed with the 

 surface pelagic fauna much as many of the abyssal types which 

 have a great bathymetrical range are dredged within the hundred- 

 fathom line or near it, and constitute a part of our shallow-water 

 fauna. 



We must remember that nearly all of the Radiolarians which 

 Chun mentions as having been taken with the tow net at a depth 

 of 300 fathoms have also been collected at the surface. The species 

 enumerated of Tomopteris of the Phronimiclse are more common 

 in deeper water than at the surface. The same is true of Stylo- 

 cheiron, of the species of Spinalis, and of the two species of Cepha- 

 lopods. But there are several species of large Appendiculariae, 

 which have thus far escaped the surface tow net of all the natu- 

 ralists who have explored the Bay of Naples. Chun seems to 



