EASTERN TROPICAL PACIFIC ASTEROIDEA. 85 



wider at tip than basally; it occurred on the surface of an adambulacral plate 

 near tlie 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 fnis. 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 Alcock'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 hne; in tumidus, the 

 abactinal plates of the distal part of the ray are more uniformly bare than in 

 intermedius; and finally, there are only foiu' 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 arc. The only growth-change noted is the greater granula- 

 tion of the abactinal plates in the adult. In the smallest specimens (R = 19 

 nun.) 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. 



