VERTICAL RANGE OF DEEP-SEA SWIMMING FORMS. 249 
ing from 500 to 570 fathoms, where the soundings indicated a depth of 622 
fathoms. A red, deep-sea Peneid, belonging to the genus Gennadas was 
found in the lower, closed part of the net.* 
There can be no doubt that the deep-sea natatory Crustacea occasionally 
come to, or very near to, the surface. The first known specimen of Hymeno- 
dora glacialis, a species whose rudimentary eyes and whose structure point to 
the depths as its normal dwelling-place, was taken at the surface, off the east 
coast of Greenland. An immature specimen of Acanthephyra agassizii was 
caught at the surface, in a dip-net, during the cruise of the “ Albatross” off 
the east coast of the United States in 1884. This specimen was kept alive 
for half an hour before it was put into alcohol.f A female of the nearly 
related, if not identical, species, A. purpurea, was captured during the 
“ National” Expedition, swimming at a depth of less than 200 fathoms. 
Spence Bate records a specimen of Gennadas secured at the surface on 
the voyage of the “ Challenger.” Amalopeneus, a genus identical with, or 
at any rate most closely allied to, Gennadas, was found during the “ Na- 
tional” Expedition at a depth of less than 200 fathoms. Yet the same 
thing was captured in the closing-net between 500 and 570 fathoms (bottom 
622 fathoms) during the “ Albatross”’ Expedition of 1891, and between 650 
and 750 fathoms during the “ National” Expedition. The genus Hucopia was 
first made known to science through a specimen recovered from the stomach 
of a penguin killed in the Antarctic Sea. This specimen was presumably 
captured by the bird in comparatively shallow water. According to Mr. 
Agassiz’s notes made on board the “ Albatross,” the same Schizopod was 
captured in the open part of the Tanner tow-net between the surface and 
300 fathoms at Station 3414 (2452 fathoms). Another individual, as we 
have seen above, was taken in the closed portion of the net at a depth of 
1000 fathoms. 
Spence Bate suggested that some of the free-swimming Crustacea of 
the deep sea may approach the surface to spawn, —a plausible theory if 
one bears in mind the sensitiveness of young animals to cold. As the bot- 
tom Crustacea of the deep sea may be supposed, from their structure and 
affinities, to have originated directly from littoral ancestors, so the deep-sea 
swimming forms have probably come from pelagic or surface species. It 
* At Challenger Exped. Station 267 (2700 fathoms), in the mid North Pacific, a specimen of Gennadus 
was captured in the open tow-net which had only been lowered to within 700 fathoms of the bottom. 
+ See S. I. Smith, in Ann. Rep. U. 8. Fish Comm. for 1885, p. 667, 1886. 
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