ANNOTATED LIST. 141 
At Mer this species is very common under large rock-fragments and coral slabs on 
the southeastern reef-flat. It acts very much like an Ophioderma and reminds one in its 
notably active movements of the large West Indian Ophioderma cinerea. One very unusual 
freak was collected, having 6 arms; the supernumerary arm, instead of being in the same 
plane as the other 5, is directly below one of them; all 6 are of approximately equal size. 
There are only 5 normal jaws, but the oral frame is obviously affected by the growth of 
the extra arm. 
Pectinura arenosa. 
Lyman. 1879. Bull. M. C. Z., 6, p. 48, pl. xiv, figs. 392-394. 
We did not meet with this species in Torres Strait, but Semon took a specimen near 
Thursday Island. It was originally described from specimens taken by the Challenger in 
Bass Strait. Koehler records a specimen taken by the Investigator off Point de Galle, 
Ceylon, while the Siboga took specimens at half a dozen stations in the Dutch East Indies. 
It is noteworthy that neither the Thetis nor the Endeavour met with the species on the 
southeastern and southern coasts of Australia. 
Pectinura yoldii. 
Ophiopeza yoldii Liitken. 1856. Vid. Med., p. 9.—1859. Add. ad Hist. Oph., pt. 2, pl. i, fig. 9. 
Pectinura yoldii H. L. Clark. 1909. Bull. M. C. Z., 52, p, 119. 
The type locality of this species is unknown, but it was probably in the East Indies, 
as the range is now known to be from New South Wales northward to Sumatra and the 
Philippines. We did not meet with yoldii in the Torres Strait region, but Semon took it 
near Thursday Island, and the Alert secured it at several stations on the Queensland coast, 
as well as in Torres Strait. It is also known from the Aru Islands. 
Ophiopezella spinosa. 
Ophiarachna spinosa Ljungman. 1867. Ofy. Kongl. Vet.-Akad. Férh., 23, p. 305. 
Ophiopezella spinosa Lyman. 1882. Challenger Oph., p. 17. 
Ophiopezella liitkeni de Loriol. 1893. Rev. Suisse Zool., 1, p. 392, pl. xiii, figs. 1—-le. 
(Plate 12, Figure 2.) 
This species, which ranges from the Philippines to the Society Islands, extends south- 
ward to the Torres Strait region, where we found it at both Friday Island and Mer. It 
was taken only once by the Siboga, but this was probably due to its secretive habits, for it 
is an inactive little species, occurring in the sand under rocks and slabs. The specimens 
taken at Mer were found on the southeastern reef-flat. 
Ophiochasma stellatum. 
Ophiarachna stellata Liungman. 1867. Ofv. Kongl. Vet.-Akad. Forh., 23, p. 305. 
Ophiopinax stellatus Bell. 1884. Alert Rept., p. 136, pl. viii, fig. C. 
Ophiochasma stellatum H. L. Clark. 1909. Bull. M. C. Z., 52, p. 121. 
We did not meet with this handsome brittle-star in the Torres Strait region, but the 
Alert took it there, according to Bell. Its known range is from Port Molle and Port Deni- 
son, Queensland, northward to the Gulf of Siam, but it is remarkable that the Siboga 
failed to meet with it. 
Ophiarachnella gorgonia. 
Ophiarachna gorgonia Miller and Troschel. 1842. Sys. Ast., p. 105. 
Ophiarachnella gorgonia H. L. Clark. 1909, Bull. M. C. Z., 62, p. 123. 
(Plate 12, Figure 5; Plate 35, Figures 4 and 5.) 
This pretty brittle-star was common at Mer and showed little diversity in color or 
size. The larger specimens, with disk 10 to 15 mm. across, are duller in color than the 
young. The specific limits of gorgonia are, however, as yet very badly drawn, and more 
extended observations on living material are necessary before positive conclusions can be 
