ANNOTATED LIST. 147 
found under large rock-fragments on the southeastern reef-flat, often in company with 
Centrechinus. The beautifully banded, black-and-white, quill-like spines, with the yellow- 
green ambulacral primaries, combine to make this an exceptionally handsome echinoid. 
Echinothrix diadema. 
Echinus diadema Linné. 1758. Sys. Nat., p. 664. 
Echinothrix turcarum A. Agassiz. 1873. Rev. Ech., pl. iiia, fig. 3. 
Echinothrix diadema Lovén. 1887. Ech. Linn., p. 137. 
This very black sea-urchin has essentially the same range as the preceding and, like 
it, has not been hitherto known from Australian seas. At Mer it was fairly common on 
the southeastern reef-flat. The large specimens were notable for having the ambulacral 
spines rusty-red instead of brown or black. In smaller specimens the interambulacral 
primaries were often more or less distinctly banded as in calamaris, but were never as clearly 
marked as in that species. Observations made at Mer lead me to think it possible that the 
two forms are not distinct species, but that we have here an illustration of a dimorphic 
species such as are well known to occur among birds. In other words, if the development 
of a single lot of eggs from an Echinothrix could be followed through, we should find that 
some became calamaris and some diadema. It is much to be hoped that some day such an 
experiment may be carried through to completion. 
STOMOPNEUSTID£E. 
Stomopneustes variolaris. 
Echinus variolaris Lamarck. 1816. Anim. s. Vert., 3, p. 47. 
Stomopneustes variolaris Agassiz. 1841. Mon. d’Ech.: Obs. Prog. Rec. Hist. Nat. Ech., p. 7. 
This species is reported from all coasts of the Indian Ocean, except only northern and 
western Australia. There is a record also from Samoa, but this needs to be confirmed, as 
it is an old one and there is no other Pacific record, so far as I know. Tenison-Woods (1880) 
describes a species of Stomopneustes from the east coast of Australia, but this is now gen- 
erally agreed to be identical with variolaris. He found his specimens at Trinity Bay, lati- 
tude about 16° S., but he believes the species also occurs at Port Denison, latitude 20.° 
On the other hand, Stomopneustes is not known from Thursday Island or vicinity, or from 
the Aru Islands, or from the northwestern side of the continent. At Mer we found only a 
single small specimen, under a rock on the southwestern reef. ‘Tenison-Wood says the 
species is very secretive and difficult to find, so it may be that its absence from many 
places is apparent rather than real. 
ECHINID/E. 
Lytechinus verruculatus. 
Psammechinus verruculatus Liitken. 1864. Vid. Med., p. 166. 
Echinus verruculatus de Loriol. 1884. Mém. Soe. Phys. Hist. Nat. Genéve, 28, No. 8, p. 21; pl. iii, figs. 3a-3e. 
Echinus angulosus Bell. 1884. Alert Rep., p. 121. 
Lytechinus verruculatus H. L. Clark. 1912. Mem. Mus. Comp. Zodl., 34, p. 253. 
It is with little doubt that I include this species among the echinoderms of Torres 
Strait. The reason for doing so is that Bell (J. c.) records Echinus angulosus for Thursday 
Island and Prince of Wales Channel. I am certain that this is a misidentification; angu- 
losus is a South African species and its occurrence in Torres Strait is highly improbable if 
not utterly impossible. On the other hand, angulosus has often been confused with ver- 
ruculatus, and as the latter occurs at the Aru Islands, and, moreover, a specimen was 
taken by me at Green Island, near Cairns, it seems to me very probable that the Alert 
specimens are this widely distributed Indo-Pacific species. Unfortunately, we failed to 
find verruculatus in the Torres Strait region. 
