ECHINODEESIATA. 133 



there is a closer and more regular granulation. The coloration, 

 which becomes blotched in the dried specimens, is found in an ex- 

 ample sent by Dr. Coppinger to consist of an irregular darkish patch 

 at each angle of the disk, and an irregular patch, extending on to the 

 marginal plates, occurs twice on the length of each arm. 



In a much smaller specimen (in which R=9) the spines are only 

 developed on one plate on either side of the apex of the angle of 

 the arm, and only two distinct spines are to be seen on the ventral 

 plates. In a specimen in which R= 16 the second spine is fairly 

 developed on some, small on others, and absent from the rest of the 

 plates nearest but one to the apex ; on all of the ventral plates a 

 third, and on some the fourth, spine is now to be made out. 



Of several specimens collected at Alert Island one has at some of 

 its angles three spine-bearing plates. 



In addition to the specimens from Thursday Island, Alert Island, 

 and Prince of Wales Channel (7 fms.), the British Museum con- 

 tains three specimens which were collected in " Australia " by 

 Macgillivray in 1862. 



29. Astropecten polyacanthus. 



M. |- T}-. p. 69. 



A fine series of ten specimens were taken in 0-5 fms., at Port 

 Jackson. In the case of two examples there are three spineless 

 ossicles succeeding the plate at the angle of the arm ; in all the 

 other cases the more ordinary condition of two such ossicles only is 

 found to obtain. The smallest specimen has E equal to 15 miUim., 

 and the largest E equal to 36 mDlim. Some variability is to be 

 noted in the tenuity of the arms. 



30. Archaster typicus. 

 M. ^ Tr. p. 65. 

 Three dried specimens from Port Denison, 4 fms. 



EETASTEE. 



Perrier, Nouv. Arch, du Mus. (2) i. p. 55*. 



31. Retaster insignia. 



Sladen, J. lAnn. Soc, Zool. xvi. p. 200. 



On receiving these specimens I recognized that they were repre- 

 sentatives of a species then undescribed ; since that time, however, 

 an account of the species has been published by Mr. Sladen in his 

 Preliminary Notice of the ' Challenger ' Collection. The foUow- 



* I am indebted to Mr. W. Percy SJailcn for this reference. 



