SALENIA VAEISPINA. 19 
ring is striated, the lines forming irregularly lozenge-shaped figures, arranged 
as they have been figured by Loven for Salenia goesiana (Loven, Eludes sur 
les Echimidees, PI. XIX.). The limits of these figures, both in the smallest 
specimen and in one measuring 2 mm. in diameter, are somewhat indistinct, 
owing to the coarse, spongy granulation of the limestone tissue of the plates 
of the abactinal system. In the majority of the young specimens examined, 
this striation could not be detected at all, and in older specimens, measuring 
from 4-8 ram. in diameter, I was unable to do more than trace portions of 
this striation on account of the granulation of the plates. 
I am now inclined to consider Salenia goesiana of Loven as identical 
with S. varispina ; it certainly agrees very closely with the young of S. 
varispina of the same size (3.5 mm.) collected by the "Blake " in the West 
Indies. These young specimens show, as I have stated above, the peculiar 
striation of the abactinal system of S. goesiana, though the size of the tuber- 
cles of the ambulacral system is somewhat smaller in the young of our 
S. varispina than in the figure given by Loven. The abnormal position of 
the madreporic body in the original type specimen of S. varispina is also 
accounted for in the description which follows. 
As regards the actinal system, in young specimens we find ten large 
plates in the continuation of the ambulacral system, spreading laterally so as 
to form a continuous ring. The space between the inner edge of these 
plates and the teeth is filled with small plates irregularly arranged. The 
ten laro-e buccal tentacles are sometimes reduced to five, one in each ambu- 
lacrum being frequently atrophied or much smaller than the other. In these 
young specimens, the sphteridia first detected in this genus by Duncan * 
stand out very prominently between the first and second pair of ambulacral 
tentacles. I have only observed one in each ambulacral area in the smaller 
specimens ; in older ones, we find sometimes as many as three at the base of 
the ambulacral area. The sphceridia of the yoimger Saleniae are nearly- 
hemispherical with a rather long peduncle ; in older specimens, they become 
more ellipsoid, and are supported upon a comparatively shorter stem. 
The primary spines of the youngest Saleniae are very remarkable ; the 
short, sharp spiny processes of the main shaft, wdiich have been figured as 
characteristic of the primary spines of Saleniae, are in these specimens 
replaced by long, slender, curved filiform processes, ai-ranged on each side 
of the shaft, and equal in length three times the diameter of the shaft. 
* Anil, and Mag. of Nat. Hist., XX. 70. 
