280 bulletin: museum of compaeative zoology. 



ASTEROIDEA. 



Archaster typicus. 



Miiller & Troschel, 1840. Monatsb. Akad. Wiss., Berlin, p. 104. 



60 specimens, 60-125 mm. in diameter. Saonek, Waigiou Island, New 

 Guinea. — 45 specimens, 50-120 mm. in diameter. Amboina. Barbour col- 

 lection. 



According to Mr. Barbour's notes, these specimens were taken in very shallow 

 water on a bottom of white sand. The color in life was orange-red, but in drying 

 the specimens nearly all trace of this color was lost, and they became pale yel- 

 lowish, with only here and there patches of orange-red. One of the specimens 

 from Amboina has 6 rays, while two of those from Saonek have only 4 rays each. 



Oreaster nodosus. 



Asterias nodosa Linne, 1758. Syst. Nat., ed. 10, p. 661. 

 Oreaster nodosus Bell, 1884. Proc. Zool. Soc. London, p. 70. 



18 specimens, Humboldt Bay, New Guinea. — 5 specimens, Sorong, New 

 Guinea. — 3 specimens, Ansus, Jappen Island, New Guinea (135° 44' E. X 1° 

 47 S'.). — 1 specimen, Amboina. Barbour collection. 



These specimens range from 80 to 300 mm. in diameter and exhibit the greatest 

 diversity in the development of the great tubercles so characteristic of this spe- 

 cies. In the youngest specimen there are present 15 tubercles, one at each radial 

 corner of the disc and two on the ridge of each ray ; those on the disc are largest 

 and most nearly pointed, while those nearest the tips of the rays are small and 

 nearly spherical. In specimens a trifle older there are 20 or 25 tubercles, one or 

 two more having developed on each ray. The pair of tubercles which are found 

 in large specimens at the proximal end of the rays, one on each side of the ridge, 

 are first seen in an individual 165 mm. in diameter, but are quite small and 

 rounded, and it is only in much larger specimens that they are fully developed. 

 The tubercle at the centre of the disc is present in only six specimens, and none 

 of these is under 200 mm. in diameter. In the largest individual it is wanting, 

 but there are 72 tubercles, arranged as follows : one large one, with two or even 

 three points, at each radial angle of the disc ; one rather small but pointed one 

 in each interradius not far from the margin, and in one interradius there are two 

 such tubercles ; eight on the ridge of each ray, with a ninth on two of the rays ; 

 the usual pair at the base of each ray ; and one, two, or even three extra tuber- 

 cles on the sides of the rays near the base. No less than 20 of the tubercles ter- 

 minate in two, three, or even four sharp, bare points. — In life, the color of this 

 species shows considerable diversity, ranging from clay-color with the large tuber- 

 cles muddy brown, or with the large tubercles deep red-brown, becoming vermil- 

 ion at the base, or with the large tubercles black, with their bases, the tips of the 



