38 PANAMIC DEEP SEA ECHINI. 



young Salenia rarix/>/na, Fig. 51, of 1.9 mm. (PI. 21, fig. ?), and one of a 

 young S. miliaris of 5 mm. (PI. 16, fig. 2), Fig. 52. 



In Acrosalenia, the ocular plate of the left posterior ambulacrum lias also 

 come in contact by one of its sides with the anal system. Figs 55, 50. 



The movement of the same pentagonal ocular plate in the right 

 posterior ambulacrum towards the anal system can be readily followed 

 in its successive stages in S. miliaris. In the youngest stage (PI. 16, fig. .') 

 it is pentagonal and well separated from the anal system ; when 8 mm. 

 in diameter. Fig. 58, the ocular plate has become truncated and hexagonal, 

 and is now in contact by one of its sides with the anal system. In a 



i 



6 linn. 



Fig.57. Sai.kma vakispina. Fig. 58. Salenia miliaris. 



specimen of 10 mm., Fig. 59, the side of the ocular plate in contact with 

 the anal system is still longer (PI. 16, fig. 6). It has become somewhat 

 indented in a specimen of 13 mm., Fig. 60 (PI. 17, fig. 2), and in an older 

 specimen of 16 mm., Fig. 61, the side of the hexagon in contact with the 

 anal system is still longer and quite deeply concave (PI. 17, fig. S). 



In a Salenia Pattersoni of 10 mm., Fig. 62, and 13 mm. Fig. 53, this same 

 ocular plate of the right posterior ambulacrum is in one case, " Blake " 

 Echini, PI. IV., Fig. 18, still pentagonal, its apex barely truncated by the 

 anal system, and in the other, " Blake " Echini, PI. IV., fig. 3, somewhat 

 more truncated, but less than in a specimen of similar size of S. miliaris. 

 A specimen of S. hastigera, " Challenger" Echini, PI. IV. figs. 6, 10, 12, of 

 13 mm. Fig. 54, shows the ocular plate only slightly truncated, much as 

 in the specimen of the same size of S. Pattersoni, Fig. 53. 



M. de Meijere 1 refers a small Salenia: obtained by the " Siboga " to 

 &'. Pattersoni. It is more likely to be the Panamic S. miliar)* or S. pacifica, 

 a Japanese species, than the West Indian species. But as he gives no 



1 "Siboga" Echinoidea, p. 43. 



