332 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



not seem to have been met with by any other observers. Consequently its real 

 relatif)usliips are still very doubtful. Philippi gives the diameter as tliree inclies 

 and the color red. It is not impossible that the species is based upon specimens 

 of the following species, Odontaster sinffularis, but I have never seen individuals 

 of Odontaster answering to Philippi's description. 



Odontaster singularis. 



Goniodiscus singularis J. Miiller and F. Troschel, 1843. Arch. f. Naturg., 9, Bd. 1, 



p. 116. 

 Pentagonaster singularis E. Perrier, 1876. Arch. Zool. Exp , 5, p. 38. 

 Gnathaster singularis W. P. Sladen, 1889. Eept. voy. "Challenger," 30, p. 286. 

 Asterodon singularis E. Perrier, 1891. Miss. Sci. Cap Horn. Zool., 3, p. K 134. 

 Odontaster singularis F. J. Bell, 1893. Proc. Zool. Soc. London, p. 262. 



Plate 2, fig:iire 4. 



The original specimens of this interesting starfish were from Cliile, but later in- 

 vestigations have shown that it is a southern species most common on the soutli 

 and west coasts of Patagonia. It reaches a diameter of 75-80 mm. and in life is 

 red ; preserved specimens are dull yellowish or brownish. The only claim which 

 this species has to a place in the Peruvian fauna is based on Leipoldt's (1895) 

 report of a small specimen (less than 30 mm. in diameter) whicli was taken be- 

 tween Iquique and Pisagua, about 20° S. lat. It is hardly likely that the north- 

 ern i-ange of Odontaster extends much above the twentieth parallel, so that its 

 occurrence in Peruvian waters is improbable. 



Nidorellia armata. 



Pentnceros (Nidorellia) armatus J. E. Gray, 1840. Ann. Mag. Nat. Hist., 6, p. 277. 

 Nidorellia armata A. E. Verrill, 1867. Trans. Conn. Acad., 1, p. 280. 



Plate 4, figure ti. 



This is a common and well-known member of the Pauamic fauna, ranging from 

 Guaymas, Mexico, to Zorritos, Peru, and also to the Galapagos Islands. The largest 

 specimen seen has R = 88 mm. The proportion R : r is quite variable, ranging 

 from 1.45 : 1 to 1.75 : 1. The number and arrangement of the abactiual spines 

 is exceedingly variable. The color in life is given by Verrill as bright scarlet. 

 Preserved specimens are more or less yellowish or brownish, seldom showing any 

 trace of red. Although this species has been taken as far south as Zorritos, it is 

 not represented in the Coker collection. A specimen in the M. C. Z. collection is 

 remarkable for appearing to have seven rays, when seen from above ; but when 

 the oral side is examined, it is found that only/y^ ambulacial furrows run out 

 from the actinostome; of these, however, two bifurcate, one near the mouth and 

 the other near the distal end, and thus arises the appearance of seven rays. 



