176 HAWAIIAN AND OTHER PACIFIC ECHINI. 



called species is only a form of cavernosus due to youthfulness, my impression 

 being that the females when first breeding have only the anterior petals depressed 

 but later in life all four petals are used as brood-pouches. I have not sufficient 

 material at hand to feel sure however. There are no specimens in the M. C. Z. 

 collection and the specimens before me from the Albatross collection are 

 neither large enough nor numerous enough to meet the need. But the largest 

 (35 mm. long) has all four petals (I, II, IV, V) equally but not greatly depressed, 

 while a smaller specimen (28 mm. long) has II and IV very greatly depressed, 

 I not quite so deep and V only a little sunken. The fact that philippii is 

 found along the east coast of Argentina, where cavernosus also occurs seems to 

 strengthen the suspicion against the validity of Lov£n's species. 



Station 2769. Off Cape Dos Bahios, Argentina. Bott. temp. 56.6°. 

 51.5 fms. Gn. m., fne. s. 



Twelve specimens. 



Abatus cordatus. 



Hemiaster cordatus Verrill, 1876. Bull. 3, U. S. Nat. Mus., p. 69. 

 Abatus cordatus Studer, 1876. Monatsb. Berlin Akad. Wisa., p. 457. 



This species is known as yet only from Kerguelen Island. 



Abatus agassizii. 



Mortensen, 1910. Swedish South Polar Exp. Ech., p. 86. 



This species is known only from South Georgia. Two specimens in the 

 M. C. Z. collection are from unknown localities. One was purchased in Ham- 

 burg. There are no other specimens .in the M. C. Z. so that Mortensen's sup- 

 position (op. cit. p. 87) that we have material from the Patagonian coast is a 

 mistake. 



Abatus shackletoni. 



Koehler, 1911. British Antarctic Exp. Biol., 2, pt. 4, p. 51. 



This species is based on a dozen specimens from Cape Royd's Bay, Ant- 

 arctica (south of New Zealand), where it is geographically quite isolated, espe- 

 cially from agaasitrii, the species to which it seems nearest. 



