ANNOTATED LIST. 71 
approximating 2 to each inferomarginal, and basally to each actinolateral; the armature 
is very simple, consisting of a furrow series of two subequal, flattened spinelets with rounded, 
slightly widened tips, standing closely side by side, and a conspicuous, oval, flattened, 
subambulacral spine; this spine is half as wide again as the tip of one of the furrow spinelets, 
its length (0.40 to 0.50 mm.) a little exceeds its width, and its free end (the narrow end of 
the oval) is distinctly pointed; this subambulacral spine is on the adoral side of the plate, 
the aboral side being occupied by 2 to 4 coarse granules. Oral plates small, their armature 
just what would be expected from the fusion of 2 adjoining adambulacrals, but the suboral 
spines are much reduced in size and have rounded tips, while the innermost spines are a 
trifle longer and heavier. Tube-feet few, in 2 well-spaced series. 
Color in life, prettily variegated with maroon, brown, and bluish-white; the figure 
(pl. 7, fig. 2) gives a better idea of it than can any description. The dried specimen is brown 
of several shades, with two noticeable but indefinite cross-bands of buffy-white on the 
rays, one near base and one near tip; the lower surface, especially the subambulacral 
spines, is lighter than the upper; as already said, the pedicellarise, both above and below, 
are conspicuous for their pure white color, but they are not at all numerous. 
Holotype, M. C. Z., No. 2313; southwestern reef, Mer, Murray Islands, Torres Strait, 
October 18, 1913. 
This dainty little sea-star was found among the crannies of some coral in water 5 or 6 
feet deep. No other specimen was found. The species differs obviously from lithodes in 
the much sparser granulation, the more slender rays, the single series of actinolateral plates, 
the single series of conspicuous abactinal plates on each ray, the large isolated papule, 
and the very different subambulacral spines. It is nearer to ritteri, but is at once distin- 
guished by the narrower rays and correlated simple arrangement of plates, by the presence 
of pedicellarie and the absence of the remarkable ‘“‘ball and socket” plates. 
CISTINA. 
Gray. 1840. Ann. Mag. Nat. Hist., 6, p. 283. 
Genotype: Cistina columbie Gray, 1840, l. c. Monotypic. 
This remarkable genus may not belong in the Ophidiasteride at all, as there is nothing 
in Gray’s diagnosis which makes its position certain, but apparently it is a member of this 
family, differing from all its relatives in the possession of a central, mobile spine on each 
skeletal plate. No sea-star has been discovered in recent years which belongs in such a 
genus, and the following is therefore still the only known species. 
Cistina columbie. 
Gray. 1840. Ann. Mag. Nat. Hist., 6, p. 283. 
There is no indication of the size of the two specimens upon which Gray based this 
species but the rays are said to be more than 8r and provided with 7 series of spines; the 
color is given as yellow; the larger specimen had 2 distinct madreporites but only one 
was found on the smaller. The locality is given as the west coast of Colombia, where H. 
Cuming collected them. The types are no longer in the British Museum and their fate is 
unknown. It is greatly to be hoped that the shores of northwestern South America may 
soon be thoroughly explored by a competent marine zodlogist, so that some of Gray’s 
remarkable species from that area may be rediscovered. 
LEIASTER. 
Peters. 1852. Monatsb. d. k. Preuss. Akad. Wiss. Berlin, p. 177. 
Genotype: Leiaster coriaceus Peters, 1852, l.c. Type designated by Fisher, 1919. 
Although Peters proposes Leiaster as a subgenus (presumably of Ophidiaster but not 
so stated) he uses the name in combination in full generic sense. The group is well circum- 
