ASTEROIDEA 97 



The very angular furrow margin of the adambulacral plates carries 8 or 9 spines and 

 3-5 others along the adoral border; subambulacral spines 2, slender, slightly curved, 

 the longer about 6 mm. at base of ray; on disk they are a little shorter, subcylindrical, 

 blunt. 



The dorsal muscle bands meet along the median line. In the specimen examined, the 

 short tendon from the inner end of band passes over the inner face of marginal plates 

 (to which it is attached) and fastens to a specialized crest of the seventh ambulacral 

 ossicle, on one side of ray, and to eighth on the other side. 



Ludwig planned a much fuller treatment of the Notomyota than the frankly pre- 

 liminary account of 1910. Unfortunately this work was never realized. No detailed 

 description and no figures of L. hirsiitus have been published. It will not be surprising if 

 eventually hirsutus and gerlachei are found to represent two races of a single circumpolar 

 species. The two examples of hirsutus studied by Ludwig were taken by the ' Valdivia ' 

 at Bouvet Island (03° 30' E, 54^ 30' S). The records oi L. gerlachei are: from much further 

 south (64° to 70°). 



In 191 1 (Fisher, 191 1, p. 127) I raised the question whether Liddiaster dawsoni is 

 congeneric with gerlachei. I have compared specimens and believe that they are. But 

 as shown by Ludwig's key (19 10, p. 453) dawsoni stands apart by the extraordinary 

 development of its spines, especially those of inferomarginal plates. 



Type locality. Southern Bellinghausen Sea, near Ice Barrier, west of Charcot 

 Island. 



Distribution. Circumpolar, Antarctic, between latitudes 70° and 64° S. Recorded 

 by Ludwig (1903) between 80° 48' and 84° 06' W, 70° and 70° 23' S, 450-560 m. 

 Koehler's specimens were taken by the Australasian Antarctic Expedition between 

 96° 13' and 145' 31' E, 64° 44' and 66° 55' S, 230-358 fathoms. 



Family ODONTASTERIDAE VerriU 



Gnathasterinae (pars) Perrier, 1894, pp. 244, 251. — Meissner, 1896, p. 92. 

 Gnaihasteridees Koehler, 1920, p. 179. 



Odontasteridae Verrill, 1899, p. 201. — Ludwig, 1903, p. 19. — Fisher, 1905, p. 302; 191 1, p. 153, 

 diagnosis — Farquhar, Trans. New Zealand Inst., xlv, 1913, p. 212. 



KEY TO THE GENERA OF ODONTASTERIDAE 



a^. A recurved, glassy tipped spine on each mouth-plate — two side by side, at each mouth 



angle. 



b^. Marginal plates decreasing regularly in size from base to extremity of rays. 



Asterodon Perrier. 



b-. Marginal plates at first increasing in size; rays dilated. Diplodontias Fisher. 



a"^. At each mouth angle a strongly recurved spine (common to the two plates), the tip of which 



is normally glassy. On either side of this, a suboral spine sometimes is enlarged and re- 

 curved and may have a short glassy tip. 



b^. Marginal increasing in size toward extremity of rays. Eurygonias Farquhar. 



b^. Marginals decreasing in size toward extremity of rays. 



