48 ‘“ ENDEAVOUR” SCIENTIFIC RESULTS 
Eleven miles south by east of Ballina, New South Wales, 
27-29 fathoms. 
East-south-east of Clarence River mouth, New South 
Wales, 35-36 fathoms. 
STELLASTER INSPINOSUS,! sp. nov. 
(Plate xiii., fig. 1-2.) 
R=—60 or 75 mms: r—Zaver 27 mm.  h—26 peebrer 
middle of ray, 11 or 14 mm. Very similar to S. incet, but 
differing sharply in several features. The marginal plates, 
though of essentially the same number, encroach more on 
both surfaces than in S. incei ; as a result, the median radial 
series of abactinal plates is accompanied by lateral series only 
to about the fourth (from interradius) superomarginal and 
there are practically no papule on the distal half of the arm, 
while in S. zncei the lateral series extend to about the eighth 
plate and the papule occur far out on the arm ; on the lower 
surface, there are only about 10 actinolateral plates in each 
area, aside from the series adjoining the adambulacrals, while 
in S. incet there are 12-20. The pedicellariz on the adambu- 
lacral plates are strikingly taller and more slender in S. 
insprnosus than in S. incet, while the big actinal spine is much 
smaller. More important is the fact that there are no spines 
on the inferomarginal plates, save that on some arms, the 
fifth (rarely the sixth) inferomarginal has a very small, flat 
spinelet, about .75 mm. long, on its outer distal corner. 
Finally, the granulation is finer in S. inspinosus than in VN. 
incet and the abactinal tubercles are fewer, 10 in the smaller 
specimen, but only 2 in the larger. Colour (dry), very pale 
brown. 
This Starfish is of particular interest not merely because it 
seems to replace S. ancet on the west coast of Australia, but 
because it is apparently a connecting link between the genera 
Stellaster and Ogmaster. Fisher? thinks “there is no 
particular similarity between Stellaster and Ogmaster,”’ but 
I am unable to agree with him. Indeed, I should be 
inclined to say there is no important difference between 
the two. Ogmaster is only a WStellaster which has lost 
its spines and granulation, and this new West Australian 
species, S. tnspinosus, is quite intermediate in that 
1. Inspinosus=without spines; in reference to the absence of spines 
of the inferomarginal plates. 
2. Fisher—Bull. U.S. Nat. Mus., Ixxvi., 1911, p. 169. 
