On a new Species of Spatangide. 67 
Figs. 12, snd 13, slender acuate spicules; fig. 14, a variety of figs. 12 
and 13. 
Fig. 15, flesh-spicules in various stages of growth, a, 6, c, d, and e. 
Figs. 16-25. Varieties of the ensiform spicule. 
Fig. 16. Variety with two shafts diverging at an angle of about 60°, and 
proceeding from a common head. 
Fig. 17, Variety in which the shaft has become straight and cylindrical 
and rounded at the end, so as to resemble mucronate forms of 
C. mucronata. 
Figs. 18-21. Various forms of inflated terminations of the ensiform spi- 
cules. @ 
Fig. 22. Extremely curved variety of ensiform spicule. 
Fig. 23. Two ensiform spicules joined together, with an angle of diver- 
gence of about 150°. 
Fig. 24. Variety with a conical spine. 
Fig. 25. Variety similar to fig. 17. 
Figs. 26-28. Chiona subulata. 
Figs. 26 and 27. Skeleton-spicules of Chona subulata. 
Fig. 28. Flesh-spicule of same. 

VIII.—Description of a new Species of Spatangide. By 
Epear A. Smits, F.Z.8., Zoological Department, British 
Museum. 
THE record of the existence of another species of the genus 
Linthia is very interesting, since up to the present time it 
comprised but a single recent form. Unfortunately I cannot give 
the locality whence the specimen was obtained with any degree 
of certainty ; however, there is some evidence which tends to 
show that it was brought either from the Pacific Islands or 
from the west coast of South America, since it was found in a 
collection of shells which consisted almost exclusively of 
species which are well-known inhabitants of those regions. 
Linthia rostrata. 
Test, seen from above, cordiform, narrowed posteriorly, 
viewed laterally much beaked behind through the prominence 
of the hinder interambulacral region above the anus, and a deep 
well-marked excavation beneath the beak; lower surface a 
little convex; viewed endways the sides appear rather flat, 
converge to an obtuse apex, and gradually round off below, 
joining the somewhat convex base. Genital openings four, 
central, very small, equal, subequidistant ; posterior pair 
scarcely wider apart than the anterior ones. Ambulacra very 
unequal, anterior lateral pair almost double as long as the 
posterior ones, moderately deeply sunken, inclined consider- 
ably towards the anterior end, yet arcuated in the opposite 
5 
