'Alert' 1881-2

134 COLLECTIONS FROM MELANESIA,
ing notes will add a little to our knowledge of this form. Not one
of the three specimens collected by Dr. Coppinger (there were two
in the 'Challenger' collection) distinctly presents that cruciform
arrangement of fibres in the dorsal areae which was so striking in the
specimens seen by Mr. 81aden ; in some of the areae it is indistinctly
marked, and in not rare cases the arose are divided into two ; the
number of pores hardly exceeds fifty ; the arose may be square as
well as rhomboidal, or may be triangular or have the angles rounded.
There is not that diflcrence in hue between the tissue covering the
areoe and that covering the spinclets which Mr. Sladen observed ;
but there may be great differences in colour, specimens being ashy
grey or deep brown. The minor radial axis is respectively 60,
48-U, and 44-7 millim.
Port MoUe, and Thursday Island (4 fms., coral).
Lyman, Prel. List, p. S*.
OPHIUROIDEA.
1. Pectinura gorgonia.
This is one of the species that extends as far west as Mauritius,
in a dried specimen from which island all the transverse bands on the
arms have disappeared, and the number of arm-spines is as many as
twelve.
Port Jackson, 0-5 fms.
2. Pectinura infernalis. (Plate Till. fig. B.)
Ophiaraclina infernalis, J/. Tr. p. 105.
Pectinura infernalis, Lyman, Lull. 31. C. Z. iii. p. 222 ; and Prel.
List, p. 3.
The three naked plates between the radial shields, which are so
markedly referred to in the original description, and are so well
seen in Mr. Lyman's figure, are not always so distinctly developed,
as may be seen by the figure which is now given.
Port Molle ; Thursday Island ; Prince of Wales Channel ; a young
specimen fi'om Port Darwin.
3. Pectinura megaloplax.
Very large naked radial shields ; disk elsewhere covered with a
coarse granulation, beneath which are largish j:)lates, somewhat
puffed ; the arras wide at their insertion, slightly carinated. Large
accessory mouth-shields present in all the interradii ; pores between
about seven rather delicate
upper arm-plates not broken.
first and second ventral arm-plates only ;
lateral arm-spines ;
* The bibliographical referenops are here chiefly confined to Mr. Lyman's
Preliminary List ' (Cambridge, U. S. A., 1880).