340 BULLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



in length (compare with the fourth specimen in table 9 above). Finally the shape 

 of the segments of the middle and distal pinnules is very similar in both, these being 

 mostly almost as broad as long and expanded towards their distal ends (fig. ISij). 



As for possible differences between Solanometra antarctica and Florometra mawsoni, 

 following this comparison there appear to be only two. Firstly the centrodorsal is 

 relatively higher in most specimens of mawsoni, the height being normally from two- 

 thirds to three-quarters of the basal width, as opposed to just under two-thirds in the 

 largest type of australis as well as in the types of S. antarctica. Secondly there are 

 LXXV cirri in the largest australis (Carpenter's figure of L applying only to the smaller 

 specimens) as opposed to rarely more than LX in mawsoni of similar size. Neither of 

 these differences are of great significance and I am inclined to think that mawsoni is 

 congeneric with Solanometra antarctica. The two specimens which I have seen collected 

 by the Australasian Antarctic Expedition off Adelie Land and named S. antarctica by 

 Mr. Clark seem to approach more closely to mawsoni considering their size, with rela- 

 tively narrower arms, longer but fewer cirri and relatively higher centrodorsals than in 

 the types of S. antarctica. A better range of specimens from the vicinity of Heard 

 Island, the type locality of antarctica, is needed to clarify this issue. 



Genus HELIOMETRA A. H. Clark. 



Asterias (part) PHIPPS, A voyage toward the North Pole, 1774, p. 284. 



Alecto (part) [LEACH], Catalogue of the contents of the museum of the Royal College of Surgeons of 

 London, pt. 4, fasc. 1, 1830, p. 14, and following authors. 



Comatula (part) J. MULLER, Monatsb. Preuss. Akad. Wiss., 1840, p. 5, and following authors. 



Comatula (Alecto) J. MULLER, Abh. Preuss. Akad. Wiss. for 1847, 1849, p. 254. 



Anledon (part) LOVEN, Ofvers. K. Vetensk Akad. Forhandl., 1866, No. 9, p. 224, and following authors. 



Antedon (Comatula) W. B. CARPENTER, Proc. Roy. Soc., vol. 18, 1870, p. 445. 



Comatula (Antedon) P. H. CARPENTER, Nature, vol. 15, 1877, p. 197. 



Heliometra A. H. CLARK, Smithsonian Misc. Coll., vol. 50, 1907, pt. 3, p. 350 (type Alecto eschrichtii 

 J. Miiller, 1841); Bull. Mus. Comp. Zool., vol. 51, No. 8, 1908, p. 246; Proc. Biol. Soc. Washington, 

 vol. 21, 1908, p. 128 (reaches maximum size in northern part of the Sea of Japan), p. 136 (referred 

 to the Antedonidae) ; Amer. Nat., vol. 42, No. 500, 1908, p. 542 (characteristic of Polar-Pacific 

 area); No. 503, p. 720 (range; variation in size), p. 724 (color); Geogr. Journ., vol. 32, No. 6, 



1908, p. 603 (occurs throughout the Polar-Pacific region), p. 604 (ecology); Proc. U.S. Nat. 

 Mus., vol. 34, 1908, p. 211 (referred to the Antedonidae, restricted), p. 212 (occurs in Japan), 

 p. 267 (relation to Promachocrinus) ; vol. 35, 1908, fig. 17, p. 119 (arm structure), p. 126 (relation 

 to Promachocrinus); vol. 36, 1909, p. 363 (closely allied to Promachocrinus), p. 365 (side and 

 covering plates; mouth often more or less excentric); Vid. Medd. Naturh. Foren. K0benhavn, 



1909, p. 122 (gregarious; 4 tons dredged at one time), p. 150 (Cominia decameros presents a re- 

 markable superficial similarity to species of this genus), p. 190 (intersyzygial interval in this 

 genus remarkably true to species); Proc. Biol. Soc. Washington, vol. 22, 1909, p. 176 (referred 

 to the Heliometrinae) ; vol. 24, 1911, p. 87 (compared with Cyclometra) ; Mem. Australian Mus., 

 vol. 4, 1911, p. 727 (route followed by this genus to the Arctic; derived from Cyclometra) ; Crinoids 

 of the Indian Ocean, 1912, p. 26 (closely allied to Cyclometra); Internat. Rev. gesamt. Hydrobiol. 

 und Hydrogr., vol. 6, 1914, p. 5 (represents Cyclometra; range and its significance); Journ. 

 Washington Acad. Sci., vol. 5, 1915, No. 3, p. 81 (probable origin); Die Crinoiden der Antarktis, 

 1915, pp. 121-126 (origin; relationships), p. 132 (covering plates), p. 182 (range). DERJUGIN, 

 Mem. Acad. Sci. St. Petersburg, vol. 34, No. 1, 1915, pp. 396, 397. F. W. CLARKE and WHEELER, 

 U.S. Geol. Surv., Prof. Paper 90-L, 1915, p. 195 (inorganic constituents of the skeleton). A. H. 

 CLARK, Journ. Washington Acad. Sci., vol. 7, 1917, No. 5, p. 127 (referred to the Heliometrinae); 

 No. 16, p. 508 (in key; geographical and bathymetrical range). F. W. CLARKE and WHEELER, 

 U.S. Geol. Surv., Prof. Paper 102, 1917, p. 23 (inorganic constituents of the skeleton). A. H. 

 CLARK, Unstalked crinoids of the Siboga-Exped., 1918, p. 240 (in key; range; includesonly glacialis). 



