132 THE ECHINODERMS OF TORRES STRAIT. 
the extreme eastern limit of its range. It is slightly larger than its allies, reaching a disk- 
diameter of 23 mm., but the arms are much shorter, rarely more than 5 or 5.5 times the 
disk. Nothing is known of the color in life or the early growth-stages. 
Ophiocoma parva. 
H. L. Clark. 1915. Mem. M. C. Z., 25, p. 292, pl. 14, figs. 8, 9. 
(Plate 13, Figure 4.) 
This interesting little species so closely resembles the young of pumila that it is only 
by actual comparison of specimens of the same size that they are to be distinguished. The 
disk in parva is more closely covered and the disk-granules are less spiniform, the arm- 
spines are shorter and stouter, and the arm-plates, both upper and under, are shorter and 
wider. It is curious that no specimens with a disk-diameter exceeding 5 mm. were found, 
for it seems probable that these are the young of a larger, 5-armed species. At Mer, parva 
was fairly common in just such situations as pumila inhabits in the West Indies, and was 
generally found associated with Ophiactis savignyi, just as pumila is. 
Ophiocoma bollonsi. 
Farquhar. 1908. Trans. N. Z. Inst., 40, p. 108. 
This species is known only from the original specimen taken in 16 fathoms between 
Stephen Island and the mainland, New Zealand. It is apparently most nearly related to 
canaliculata, with which species it has several important characters in common, notably 
the large adoral plates. As Farquhar says the disk granules become spiniform at the disk- 
margin orally, it has seemed necessary in preparing the artificial key to put it in the pumila 
section of the genus, but, as already said, it has no special affinity for these forms. 
OPHIOPTERIS. 
E. A. Smith. 1877. Ann. Mag. Nat. Hist. (4), 19, p. 306. 
This genus is remarkable, not only for the peculiar and characteristic upper arm- 
spines, but for the distribution of the species, one of which occurs only in New Zealand 
and the other only on the coast of southern California. Neither species is at all common 
and nothing is known of habits or growth-changes. The two are very closely allied, and, 
in the absence of more abundant material, it is difficult to determine what the essential 
differences are, yet there is little doubt that they are quite distinct. 
Key to the Species of Ophiopteris. 
Color black or very dark brown, more or less reddish orally; arm-plates, especially the upper, not very 
markedly wider than long; uppermost arm-spine nearly circular......... 02.0 ccc eevee cee ee antipodum 
Color brown, often more or less variegated and arms distinctly banded; arm-plates markedly wider than 
long; uppermost arm-spines somewhat more elongated............0..000 cece eececuvecevees papillosa 
Ophiopteris antipodum. 
E. A. Smith. 1877. Ann. Mag. Nat. Hist. (4), 19, p. 306, pl. xv. 
This is the New Zealand species and both of the specimens in the Museum of Com- 
parative Zodlogy are from Island Bay, near Wellington. But Mr. Farquhar writes me 
that it is very rare, even there, and he has very seldom met with it. The larger of our 
two specimens is about 15 mm. across the disk. 
Ophiopteris papillosa. 
Ophiocoma papillosa Lyman. 1875. Illus. Cat. M. C. Z., No. 8, pt. 2, p. 11. 
Ophiopteris papillosa McClendon. 1909. Univ. Cal. Publ., Zool., 6, p. 49, pl. v, figs. 28, 29. 
This species ranges from Monterey to San Diego, from the shore out to at least 30 
fathoms, but it is by no means common. McClendon gives ‘‘ Lower California” as a local- 
