ECHINODEEMATA. 169 



24. Actinometra alternans. 

 P. M, Carpenter, Notes Lei/d. Mus. iii. p. 208. 



An example of this interesting species was determined for me by 

 Mr. P. H. Carpenter ; tlie stumps of two cirri are still present. 

 Port MoUe. 



25. Actinometra paucicirra. (Plate XVII. fig. A, a.) 



Centrodorsal small, low, rounded, with. 5 or 6 marginal cini of 

 15-18 joints, a number of which are longer than broad ; the penul- 

 timate spine exceedingly small. 



First radials visible, second radials very wide, not in contact, 

 united with the third by a syzygy. Twenty arms ; two joints in the 

 distichals united by a syzygy, the more prominent joints in contact. 

 First and second brachials united by a syzygy ; third and fourth 

 pretty regularly oblong ; the fifth faintly wedge-shaped ; after this 

 the wedge-shaped form becomes more marked, but the edges do not 

 overlap. 



Syzygies on the eighth and twelfth, then from 3-5 joints between 

 each. . First pinnules longer than the second, and the third than the 

 fourth; the first alone of any considerable size ; its joints produced 

 into very prominent edges. The succeeding pinnules small; later 

 out they enlarge somewhat, but are never at all long. 



Arms about 70 millim. long, cirri 8 millim., disk 7 millim. in 

 diameter. A slight development of calcareous deposit between the 

 bases of the arms. 



Colour creamy white above, rather darker below. 



Prince of Wales Channel ; Thursday Island. 



26. Actinometra multifida. 



Comatula multiflda, J. Mull, p, 26. 



Percy Island, Queensland; Albany Island; Prince of Wales 

 Channel. 



27. Actinometra variabilis. (Plate XVII. fig. B, a.) 



Centrodorsal of moderate size, concave in the middle, with 10 

 marginal cirri, of about 16 joints ; very faint indications of spines 

 on the most distal only. 



First radials visible, second exceedingly wide in proportion to 

 their length, in contact ; the third almost perfectly triangular, not 

 a syzygy ; there are normally three distichals, and the axillary is a 

 syzygy ; there are two palmars and no syzygy, or three palmars and 

 a syzygy. If there is another division there are two joints, and the 

 axillary is not a syzygy. Arms from 60-90. 



