REPORT ON THE PYCNOGONIDA. 63 
The last four joints describe a spiral curve; so that the tenth lies parallel to the seventh. 
Their inner surfaces are furnished with numerous rows of very flat spines. In the oldest 
specimen there are about twelve rows, making the total number of spines for every joint 
several hundreds. None of these spines, however, show the original shape ; they are all of 
them broken by use or by age, and those placed towards one side especially are very short 
and rudimentary. On the other side they grow longer (Pl. X. fig. 2), and, covered 
by this outermost row of longest spines, some short thimble-shaped knobs (fig. 5) are to 
be observed. Such is at least the condition of the flattened spines on the last four joints of 
the ovigerous legs of the gigantic male dredged at Station 146. The specimen second 
in size is a great deal smaller and in all probability is not quite adult. Here the 
spines, placed in about eight rows, show a much more regular shape (fig. 8); their 
margins are furnished anteriorly with very small hairs. These hairs are rather 
firm, are not at all injured by the action of alcohol, and must not, I believe, be con- 
sidered as cilia. The spines are in the middle a great deal narrower, and broader again 
at the extremity, the broader part has the shape of a rhomb. In the earliest stage the 
spines are much smaller and beautifully spatulate. The small hairs extend here to beyond 
the middle (Pl. X. fig. 4). 
This species has exceedingly iene legs. The first three joints are very small, the 
three following very long; the fourth is the longest, the fifth a Jittle shorter, the sixth 
again a little shorter; the two last joints are small again ; the second tarsal is only half 
as long as the first. The claw measures about one-third the length of the second tarsal 
jomt; there are no auxiliary claws. The joints of the leg, from the fourth to the 
eighth, gradually decrease in thickness. The hairs, which on the legs of the large adult 
specimen are extremely small and oo are stronger and more numerous on the legs of 
_ the younger specimens. 
In regard to the sexes of the specimens of this species dredged during the voyage of 
the Challenger, Iam sure only of the gigantic specimen. This is a male ; it shows genital 
openings on the ventral surface not very close to the distal margin of the second joint of 
the two posterior pairs of legs. About the other specimens, whose genital openings I failed 
to observe, I am in doubt whether they are young males or females. The colour of the 
specimens is light yellow, nearly the same as that of all other Pycnogonids preserved in 
spirits. The large full-grown male, however, is of a much darker orange-red colour, with 
beautiful red bands over the proboscis, at the extremity of the joints of the legs, &e. 
Habitat.—Colossendeis gigas, seems to occur in different parts of the southern 
ocean; it was dredged at 
Station 146. December 29, 1873. Lat. 46° 46’S., long. 45° 31’ E. Depth of the 
sea, 1375 fathoms. Temperature of the bottom, 15° C. Sea bottom, globigerina 
00ze. 
Station 147. December 30, 1873. Lat. 46° 16’ 8, long. 48° 27’ E. Depth of the 
