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 area? which was so striking in the 

 specimens seen by Air. Sladen ; in some of the area? it is indistinctly 

 marked, and in not rare cases the arese are divided into two ; the 

 number of pores hardly exceeds fifty ; the areac may be square as 

 well as rhomboidal, or maybe triangular or have the angles rounded. 

 There is not that difference in hue between the tissue covering the 

 area? 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 447 millim. 



Port Molle, and Thursday Island (4 fms., coral ). 



OPHIUROIDEA. 



1. Pectinura gorgonia. 

 Lyman, PreL List, p. 3*. 



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 infemalis. (Plate YIII. fig. B.) 



Ophiarackna infemalis, JI. Tr. p. 105. 



Pectinura infemalis, Lyman, Lull. 31. C. Z. iii. p. 222 ; aud 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 from Port Darwin. 



3. Pectinura megaloplax. 



Very large naked radial shields ; disk elsewhere covered with a 

 coarse granulation, beneath which are largish plates, somewhat 

 puffed ; the arms wide at their insertion, slightly carinated. Large 

 accessory mouth-shields present in all the interradii : pores between 

 first and second ventral arm-plates only ; about seven rather delicate 

 lateral arm-spines : upper arm-plates not broken. 



* The bibliographical references are here chiefly confined to Mr. Lyman's 

 Preliminary List ' (Cambridge, U. S. A., 1880). 



