93 
reverse of what one would expect. The absolute diameters in milli- 
meters range from R. 58, r. 30, to R. 72, r.. 37, dry ; and, in alcohol, 
R. 66, r. 33, to R. 76, 7.34. This variation results in slight differences 
in outline, the arms being longer or shorter, and the interbrachial less 
or more excavated. 
(b.) The arms are sometimes narrow at the base, sometimes broader ; 
in some cases more pointed, in others more rounded at the apex. 
(c.) The number of supramarginal plates increases with the size : 
in the smallest (R. = 58) there are 10 supramarginals on each side of 
an arm, omitting the odd interbrachial plate; the highest number 
is 16, in a specimen in which R. = 76 mm. 
(d.) The madreporite is in some but little larger than-a neighbouring 
abactinal plate ; in other cases, more than twice the size: it may be: 
circular, or wregularly pentagonal. In the largest individual it mea- 
sures 10 mm. in diameter. 
Pentagonaster pulchellus Gray. 
Astrogonium pulchellum Sladen, 1889. Farquhar, Proc. Linn. Soc. 
N.S:W., xxiii, 1898, p. 310.* 
Station 29. 
A single specimen was obtained off Oamaru. 
R. 40, r. 25 (which is smaller than some other specimens in this 
Museum, one of which has R. 50, r. 30). 
It has the swollen marginals at the ends of the arms, typical of the 
species, the tip of the arm measuring 15 mm. across. 
The abactinal plates are flat, except along the middle of each 
arm, where each is slightly convex. 
Although this species has usually been referred to the genus Astro- 
gonium Miiller and Troschel (1842), yet, as Verrill (1899) pointed out, 
Gray (1840) had already placed the species in the genus Pentagonaster, 
of which it stands as the geno-type. 
This species is described and figured by Gray [20, p. 11, pl. viii, 
fig. 3.] 
Localities. —Off Oamaru, at a depth of .25-30 fathoms, shell 
gravel. [Foveaux Strait, Cook Strait, Chatham Islands (F.).] 
Pentagonaster abnormalis Gray. 
Astrogonium abnormale, auct. Farquhar, loc. cv., 1898, p. 310, for 
synonymy. 
Plate VIII, fig. 5. 
Stations 15, 16, 22 
This is a common species off the east coast, of Otago, for, in addition 
to > the ten specimens, obtained by the ' ‘Nora Niven’ between Otago: 
‘3 Ristond of te Pah. each species its full synonymy a references. 
it will suffice to refer to this paper of Mr. Farquhav’s. 
