salenim;. 



37 



S. varispina. The specimen is also intermediate in size between the speci- 

 mens of S. varispina collected. The arrangement of the ambulacral plates as 

 far as we can judge from the figures of Loven, 1 is similar to that of Salenia 

 Pattersoni (PL 20, fig. J). 



1,9 mm. r > »""• 13 ram. 



Fio. 51. Salenia varispina. Fig. 52. Salenia miliaris. Fig. 53. Salenia Pattersoni. 



In PI. 21, fig. 1, we can see a small triangular plate at the actiuostome 

 in the median interambulacral zone, — very probably the remnant of the 

 primitive primordial plate. No trace of primordial plates could be traced in 

 Salenia miliaris. 



In none of the young stages of Salenia varispina, Fig. 51; miliaris, Fig. 52; 

 Pattersoni, Fig. 53, and hastigera, Fig. 54, do any of the ocular plates come 



13 mm. 



Fig. 54. Salenia uastigeka. 



7 3 mm. 9 mm. 



Fig. 55. Acrosalenia spinosa. Fig. 56. 



in contact with the anal system, while in the young Acrosakn/'a spinosa, 

 Fig. 55, of 7, and Fig. 56, of mm., the ocular plate of the right posterior 

 ambulacral is well in contact by one of its sides with the anal system 

 (PI. 22, fig. 5). Compare this with the figures of the apical system of a 



1 Loven, Echinoide'es, PI. XIX, figs. 162, 165. 



