76 THE ECHINODERMS OF TORRES STRAIT. 
Pharia pyramidata. 
Ophidiaster (Pharia) pyramidatus Gray. 1840. Ann. Mag. Nat. Hist., 6, p. 284. 
Ophidiaster porosissimus Liitken. 1859. Vid. Med., p. 33, 87. 
Pharia pyramidata Sladen. 1889. Challenger Ast., p. 784.—H. L. Clark. 1910. Bull. M. C. Z., 52, p. 335, 
pl. 5, fig. 2. F 
This large and easily recognized sea-star ranges along the western coast of America 
from the Gulf of California to Zorritos, Peru. It has been recorded from Valparaiso, but 
it is highly improbable that it occurs naturally so far south. Large specimens have R= 
150-160 mm. Preserved specimens are dull purplish or reddish brown, but there is some 
doubt about the color in life. In 1868 Verrill said the color is ‘‘in life variegated above 
with purple and brown,”’ but in 1871 he said: ‘‘The dry specimens in best condition are 
light straw-color beneath; the poriferous zones are bright orange; the rows of large plates 
on the back and sides olive-green; madreporic plate large, dark olive-green.”” Such a 
coloration seems quite impossible for a sea-star which was only ‘‘variegated purple and 
brown” when alive, but indicates what the real color in life may be. 
OPHIDIASTER. 
Agassiz. 1835. Mem. Soc. Sci. Nat. Nefichatel, 1, p. 191. 
Genotype: Asterias ophidiana Lamarck, 1816. Anim. s. Vert., 2, p. 567. Monotypic. 
More species have been referred to this genus than to any other in the family, not 
even excepting Linckia, but most of them belong elsewhere or are purely nominal forms. 
Agassiz’s diagnosis shows that there was no clear distinction in his mind between Ophidiaster 
and Linckia, but Gray in 1840 distinguished them perfectly. Indeed, he showed an extra- 
ordinary grasp of the essential differences between the various sea-stars now placed in 
the Ophidiasterids, grouping them in 14 consecutive genera and subgenera. While it 
need not be maintained that these 14 groups are of equal merit, they seem to be remarkably 
natural and, as already said (p. 36), it has seemed to me desirable to restore them to use. 
Even in dealing with the perplexing genera Linckia and Ophidiaster, Gray shows no con- 
fusion, for every one of his 7 species of Linckia s.s. is a true Linckia and his 3 Ophidiaster 
s.s. are true Ophidiasters except leachii, which is a Leiaster, a genus not easily distinguished 
from Ophidiaster when the specimens are dry. 
This remarkable taxonomic achievement of the English zodlogist stands out even 
more strikingly when contrasted with the attempt of Miiller and Troschel (1842) to group 
the members of the family. They recognized but two genera, Ophidiaster and Scytaster, 
abandoning Linckia altogether. In 1866 von Martens went to the other extreme, aban- 
doning Ophidiaster altogether and using Linckia in a very broad sense. In 1871 Liitken 
clearly recognized the distinctness of Linckia, Ophidiaster, Scytaster, and Leiaster. His 
only slip was in including Mithrodia in the same family, but Miller and Troschel had 
actually not distinguished Mithrodia from Ophidiaster, although Gray had placed it in an 
entirely separate section of his system. Perrier in 1869 was a follower of Miiller and 
Torschel’s simple plan, but in 1875 he accepted Liitken’s results and used Ophidiaster in a 
definite way. He failed, however, to appreciate Gray’s work and hence his Ophidiaster 
is still a rather heterogeneous group. Sladen, in the Challenger Report (1889), followed 
Perrier in his use of Ophidiaster, but Ludwig in 1897 pointed out that Hacelia Gray was 
quite distinct from typical Ophidiaster and should be given generic rank. This view was 
concurred in by Fisher, 1911. 
The following list shows the species which have been assigned to Ophidiaster, or at 
least the specific names which have been published in conjunction with that generic term, 
and the conclusions I have reached regarding their true position. Obviously, many of 
these conclusions were reached by other writers years ago. 
