EEPOET ON THE CEINOIDEA. 149 



Disk 12 mm.; spread at least 25 cm. 



Locality.— Station 308, January 5, 1876 ; lat. 50° 8' 30" S., long. 74° 41' 0" W.; 

 175 fathoms; blue mud. One specimen. 



Remarks. — This species resembles Antedon australis in the length of the middle 

 joints of the third pinnule, but it is altogether a much larger form, with considerably 

 longer arm -joints than occur in that species. In this respect Antedon rhomboidea and 

 Antedon magellanica have the same relation to Antedon australis and Antedon 

 antarctica that the northern species Antedon quadrata has to Antedon eschrichti. 

 Antedon magellanica has never yet been properly described, the type specimen having 

 been regarded merely as a variety of Antedon eschrichti, 1 although its arm-joints are 

 mostly quadrate and as long as or longer than wide. It has many points of resemblance 

 with Antedon rhomboidea, but there may be over fifty cirrus-joints, while some of the 

 middle joints of the second pinnule are longer than wide. It is nearly half as long again 

 as the corresponding pinnule in an equal sized specimen of Antedon rhomboidea, while 

 the third pinnule is considerably shorter than the second. Several examples of the type 

 were obtained by the Italian corvette " Vettor Pisani," and I hope soon to be able to 

 describe them at length. 



5. Antedon quadrata, n. sp. (PI. XXVI. figs. 1-3 ; PI. XXVII. figs. 1-13 ; woodcut, 

 figs. 4, a, b, on p. 154). 



C 



Specific formula — A.y. 



1878. Antedon celficus, von Marenzeller, Denkschr. d. k. Akad. d. Wiss. Wien, 1877 [1878], 

 Ed. xxxv. p. 380. 



1880. Antedon celticus, d'Urban, Ann. and Mag. Nat. Hist., 1880, ser. 5, vol. vi. p. 380. 



1881. Antedon celtica, Duncan and Sladen, Memoir Arctic Eclnnodermata, London, 1881, 



pp. 75-77, pi. vi. figs. 5, 6. 



1881. Antedon celtica, P. H. Carpenter, Zool. Anzeiger, 1881, Jahrg. iv. p. 521. 



1882. Antedon celtica, Bell, Proc. Zool. Soc. Lond, 1882, p. 534. 

 1882. Antedon celtica, P. H. Carpenter, Ibid., p. 746. 



1884. Antedon quadrata, P. H. Carpenter, Proc. Koy. Soc. Edin., 1884, pp. 375-377. 



1886. Antedon quadrata, P. H. Carpenter, Bijdragen tot de Dierkunde, 1886, 13 Aflevering, 



vi. p. 7, pi. i. fig. 6. 

 1886. Antedon Eschrichtii, Levinsen {jpars), Dijniphna-Togtets zoologisk-botaniske Udbytte, 



Kj0benhavn, 1886, p. 410. 

 1886. Antedon quadrata, Fischer, Die Osterreichische Polarstation Jan Mayen, Bd. iii., "Wien, 



1886, Echinodermen, p. 3. 



Centro-dorsal hemispherical, bearing fifty to seventy cirri, with about thirty to 

 thirty -five joints, several of which are longer than wide ; the later joints sharpened 

 dorsally but not distinctly carinate. 



1 See Proc. Zool. Soc. Lond., 1882, p. 650. 



