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70 ‘* ENDEAVOUR” SCIENTIFIC RESULTS. 
points, there are only 3 series, a median, and one lateral on 
each side. Each mesh contains one or more papule, but in 
the dry specimen, it is difficult to determine their presence. 
Each plate of the skeleton bears a single, slender, pointed spine, 
1-1.5 mm. long ; also numerous small pedicellaria, which may 
be either on the plate itself or on the spine or on both ; often 
the spines, particularly along the actinal margin, have large 
wreaths or half-wreaths of pedicellarize. Adambulacral plates, 
15 to 5 marginals, at base of arm ; armature of 2 spines, in a 
transverse series ; they are about 1.5 mm. long and subequal 
or the outer a trifle the longer ; the outer is also a trifle more 
adoral. There are a very few, scattered, small pedicellarize 
just within the margin of the ambulacral furrow, which is 
notably broad and has the tube-feet in two distinct and well- 
separated series. Oral plates not large, but projecting dis- 
tally so as to slope sharply into the mouth; each one bears 
3 smooth spines ;_ one on the actinal surface, which is similar 
to, about as long as, but stouter than the adambulacral spines; 
a second is still stouter and blunter and stands at the proximal 
end of the plate ; while the third is much shorter than either 
of the others, is situated at the proximo-lateral corner of the 
plate and extends straight out across the ambulacral furrow ; 
it carries a few small pedicellariz. Madreporite large (2 mm. 
across), conspicuous, near margin of disk. Colour (dry) ; 
skeleton and spines, white ; membranes and feet, brown. 
This species is quite unlike the Atlantic members of the 
genus but bears considerable resemblance to P. improvisus, 
Ludwig, from the Galapagos Islands. It differs noticeably 
in the armature of the oral plates, however, as well as in some 
other details (number of papule, length of spines, etc.). The 
inequality of the arms suggests that schizogony occurs, but 
it is possible that the condition of the present specimen is 
accidental. 
Loc.—East of Maria Island, Tasmania, 78 fathoms. 
Family ASTERITD. 
Genus ALLOSTICHASTER, Verrill. 
ALLOSTICHASTER POLYPLAX (Miller and Troschel). 
Asteracanthion polyplax, Miller and Troschel, Arch. f. 
Naturg., x. i., 1844, p. 178. 
Allostichaster polyplax, Verrill, Harriman Alaska Exped., 
Starfishes, 1914, p. 363. 
It is a little odd that this well-known Australian Starfish 
Should have been taken only at Oyster Bay, Tasmania ; not 
