240 BULLETIN 76, UNITED STATES NATIONAL MUSEUM 



Diagnosis Small antarctic, or southern, paedophoric species with monacanthid 

 adambulacral plates and typically a well-developed, irregularly reticulate abactinal 

 skeleton, overlaid by a thin pulpy skin; carinals in more or less evident longiseries; 

 dorsolateral plates usually rather numerous, forming an irrgular net, or arranged in 

 subregular loi (marginals not relatively very broad; inferomarginal 



plates and spines ool i sharp ventrolateral border to ray ; crossed pedicallariae 



when numerous, i 1 around abactinal and marginal spinelets; straight pedi- 



cellariae usually lanceolate, sometimes robust, ovoid, or subspatulate; gonads open 

 vent rally; a series of actinal plates, usually spiniferous, but absent in young specimens. 



The relation of this group to Anasterias is discussed under that genus. 



Parastickaster Koehler appears to represent the maximum development of 

 skeleton. In addition to the 6-rayed type, Doctor Koehler describes two other 

 species -directus having five rays and sphaerulatus with six or eight rays. These 

 are all stout-armed, monacanthid sea stars, having a rather irregular dorsolateral 

 skeleton, small carinals, and relatively much smaller superomarginals than has 

 Stichaster, to which Koehler compares the genus. The gonads open ventrally and 

 the young are carried in a cluster over the mouth. The stubby inferomarginal 

 spines are arranged in short, oblique, transverse series. 



All these features are characteristic of " Sporasterias spirabilis" (Bell) and 

 adult "S. nigispina" (Stimpson). In fact P. mawsoni suggests a 6-rayed Sporas- 

 terias spirabilis. The paedophoric habit and monacanthid adambulacrals are out- 

 standing common characters of Sporasterias and Parastickaster, and the genera seem 

 to be confluent. 



1. SPORASTERIAS ANTARCTICA (LUtken). 



Asteracanthion antarcticum Lutken, Vidensk. Meddel., 1856, p. 105. 



Asterias rugispina Stimpson, Proc. Boston Soc. Nat. Hist., vol. S, lSdO, p. 267. — Leipoldt, 



Zeit. Wiss. Zool., 1895, p. 563; literature. 

 Ast nghami Perrier, Rev. Stell., 1S75, p. 75. 



AsU lis Bei/l, Proc. Zool. Soc, 1881, p. 513, pi. 48, fig. 4. 



Asterias verriUi Mr.i.i., Proc. Zool. Soc, 1881, p. 513, pi. 47, figs. 3, 3a. 

 lesi Perrier, Comptes-rend., 1SS6, p. 114*;. 

 orasterias spirabilis Perrier, Expeel. sci. Travailleur et Talisman, 1894, p. 107. 

 Aslerias Has) antarctica Meissner, Arch. Xaturges, 1896, p. 105, pi. 6, fiVs. 7, 



7a-7b; liti rat lire. 

 Sporasterias antarctica Ludwig, Expend, antarct. Beige, 1903, p. 39; 1905a, p. 70. — Koehler, 

 1917, p. 10; 1920, p. 78, pi. 18, figs. 1-4; pi. 28, figs. 1-4; 1923, p. 14, pi. 7, fig. 4. 

 antarctica Fishi r, Ann. Mac. Nat. Hist., ser. 9, vol. 18, 1926, p. 197. 



To this synonymy Leipoldt 1895, p. 563, adds: Asleracanikion varium Philippi, 

 A. fidgens Philippi, as well as several species, such as Anasterias minuta, Asterias 

 perrieri Smith, Asterias rupicola Yen-ill, and Calvasterias stolidoia Sladen, which 

 I consider to be distinct. 



Among the above list of synonyms there are undoubtedly representatives of 

 several well-marked formae, but material is lacking by which a scheme can be 

 constructed. 



N errill (1914, p. 353), writes of this complex of forms as "the most common and 

 abundant littoral and shallow-water starfishes of both coasts of Tierra del Fuego 

 and Magellan Strait." 



