EASTERN TROPICAL PACIFIC ASTEROIDEA. 85 
wider at tip than basally; it occurred on the surface of an adambulacral plate 
near the middle of the arm. In the smallest specimen, half a dozen of these 
pedicellariae were found on the actinolateral plates. 
Color, in alcohol, light yellow-brown, which dries out to a dingy whitish. 
Station 4656. Eastern Tropical Pacific, 6° 54’ 36” S., 83° 34’ 18” W., 2,222 fms. Bott. temp. 35.2°. 
Fne. gn. m., mang. nod. 
Station 4672. Peru; southwest of Palominos Light House, 88 miles, 2,845 fms. Bott. temp. 35.2°. 
Fne. dk. br. infus. m. 
Twelve specimens. 
The holotype is from Station 4672. 
The discovery of a second species of Litonotaster is one of the interesting 
results of the work of the ALBaTRoss in the Tropical Pacific, for the genus was 
hitherto known from only the deep waters of the West Indies, Koehler having 
shown (1909. Investigator Ast., p. 73) that Aleock’s (1893. Ann. Mag. Nat. 
Hist., (6), 11, p. 90) identification of an Indian starfish as identical with the 
West Indian form was quite erroneous. The genus seems to be a very well- 
marked one and the present species shows its distinctive characters perfectly. 
But the differences between tumidus and intermedius, the genotype, are obvious, 
particularly in the three following points: — in tumidus the abactinal plates 
of the ray extend clear to the terminal plate while in intermedius this is not’ the 
case, the distal superomarginals meeting in the radial line; in tumidus, the 
abactinal plates of the distal part of the ray are more uniformly bare than in 
intermedius; and finally, there are only four or five adambulacral spines in 
tumidus as against seven or eight in intermedius. 
The present species does not show a great deal of individual diversity except 
in the body-form, already referred to, which is due to the amount of flattening 
of the interbrachial are. The only growth-change noted is the greater granula- 
tion of the abactinal plates in the adult. In the smallest specimens (R = 19 
mm.) most of the disk-plates and those on the proximal part of the arms, as 
well as the distal plates on the arms, lack granules on the surface, only the 
marginal series being present. The madreporite is relatively, as well as actually, 
very much smaller in the small specimens than in the larger. 
