68 Mr. E. A. Smith on a new Species of Spatangide. 
direction ; posterior petals equally deep as the anterior, a 
little narrower, very short, sinuous, diverging at their extre- 
mities; pores rather larger than in the recent type of the 
genus (L. australis), connected by a shallow groove; the nar- 
row ridges separating them bear a few minute tubercles on 
their outer half. Peripetalous fasciole narrow, very angular 
and sinuous; in the posterior lateral interambulacrum it 
passes close to and almost parallel with the hinder furrows 
for about eight ninths of their length, then descends suddenly, 
forming an acute angle, and running close to the anterior 
lateral furrow, with two slight bends in its course, passes 
round the termination of the furrow in an abrupt curve, and 
rises in a straight line somewhat obliquely towards the ante- 
rior ambulacrum, where it suddenly descends at a right angle 
and parallel with the furrow, and then, after a short distance, 
a little above the ambitus, crosses in a curve the shallow 
groove. The lateral follows a similar course to that of aus- 
tralis, Anterior ambulacral groove almost as deep as the 
others, becoming gradually shallower towards the ambitus, 
with a series on each side of remote and very minute double 
pores, alternating with one another on each side, those just 
above the fasciole being about two millimetres apart. Tuber- 
culation very like that of LZ. australis. Plastron narrowly 
cordate, convex, not much narrowed towards the mouth, and 
not reentering at the aboral end. Mouth broad, narrow. 
Anal opening ovate, acuminate above and below. The colour 
is that of cork, mottled with a darker hue in the middle of the 
plates. 
Length nearly 1} inch, width at ambitus 13, height 1. 
Hab. Pacific Islands (probably). 
This species, of which I have only seen a single spineless 
specimen, has much of the general character of L. australis of 
Gray. Still there are so many differences, which, although 
perhaps small individually, in the aggregate become of much 
importance, that I certainly think they point out the specific 
distinctness of the form above described, and show that it 
passes the limits of an individual variation. 
The position of the apex and genital pores is very different ; 
the form is totally distinct, resembling very considerably that 
of the fossil Wicraster cor-anguinum, var. rostratus ; the pro- 
portion and inclination of the ambulacra and the course 
of the fasciole also show considerable variation. Besides 
these differences there are others—namely, the greater depth 
of the anterior ambulacrum and the remoteness and minute- 
ness of the pores on each side of it ; and in specimens of equal 
size of the old species the pores of the other ambulacra are 
