Report on the zoological collections made in the Indo-Pacific Ocean ...

134 COLLECTIONS FROM MELANESIA,ing notes will add a little to our knowledge of this form. Not oneof the three specimens collected by Dr. Coppinger (there were twoin the 'Challenger' collection) distinctly presents that cruciformarrangement of fibres in the dorsal areae which was so striking in thespecimens seen by Mr. 81aden ; in some of the areae it is indistinctlymarked, and in not rare cases the arose are divided into two ; thenumber of pores hardly exceeds fifty ; the arose may be square aswell as rhomboidal, or may be triangular or have the angles rounded.There is not that diflcrence in hue between the tissue covering theareoe and that covering the spinclets which Mr. Sladen observed ;but there may be great differences in colour, specimens being ashygrey or deep brown. The minor radial axis is respectively 60,48-U, and 44-7 millim.Port MoUe, and Thursday Island (4 fms., coral).OPHIUROIDEA.Lyman, Prel. List, p. S*.This is one of the1. Pectinura gorgonia.species that extends as far west as Mauritius,in a dried specimen from which island all the transverse bands on thearms have disappeared, and the number of arm-spines is as many astwelve.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 somarkedly referred to in the original description, and are so wellseen 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 youngspecimen fi'om Port Darwin.3. Pectinura megaloplax.Very large naked radial shields ; disk elsewhere covered with acoarse granulation, beneath which are largish j:)lates, somewhatpuffed ; the arras wide at their insertion, slightly carinated. Largeaccessory mouth-shields present in all the interradii ;pores betweenfirst and second ventral arm-plates only ; about seven rather delicatelateral arm-spines ; upper arm-plates not broken.* The bibliographical referenops are here chiefly confined to Mr. Lyman'sPreliminary List ' (Cambridge, U. S. A., 1880).