ASTEROIDEA 87 



Leptychaster magnificus (Koehler) 



Asterias longsiaffi Bell? 1908, p. 7. In any event the name is a nomen nudum, since the printed matter 



which follows it is misleading, and in no wise describes the specimen. I have seen the type. 

 Priamaster magnificus Koehler, 1912, p. 92, pi. 8, figs, i, 3, 8. — 1920, p. 255. 



St. 599. Off Loubet Land, east of Adelaide Island, bf 08' S, 69° o6i' W, 203 m., i specimen. 



The specimen measures R 1 17 mm., r 25 mm. ; R=3-3 r ; breadth of ray at interradial 

 line, 41 mm. It is therefore smaller than Koehler's type which measured R 192 mm., 

 r 63 mm., br 70 mm. 



Koehler (19 12) has given a detailed description and excellent figure. Later (1920) he 

 recognized the close similarity between his Priamaster and Leptychaster but could not 

 come to the point of abandoning Priamaster. Character by character Priamaster is a 

 Leptychaster. I have ascertained that the gonads have a distribution very similar to 

 those of L. kerguelenetisis, a specimen of which I have examined. This is one of the 

 examples mentioned by Sladen (1889, p. 186) from Marion Island, R 38 mm., r 11 mm. 

 In typical Leptychaster, both male and female, the gonads form a series of tufts or lobes, 

 slightly spaced, depending from the genital stolon and extending far along the ray. In 

 L. kerguelene?isis the ovaries form a series close to the inner edge of superomarginal 

 plates for half the length of the ray. In the giant specimen of L. accrescens the ovaries are 

 far removed from the margin (a little nearer radial line than margin) and the long, 

 divided lobes form rather voluminous, spaced, tufts extending for two-thirds the length 

 of ray. A male specimen (St. 42) having R no mm. has a similar distribution of the 

 gonads. In L. magnificus the gonads are distributed precisely as in accrescens. 



The two large species differ from the small kerguelenetisis in having the genital stolon, 

 and its dependent gonads, far removed from the margin of abactinal area. If Priamaster 

 is a valid genus, then accrescetis is also a Priamaster. 



The large, 4-ranked tube feet are characteristic of both magnificus and accrescens. In 

 young accrescens (R 64 mm.) the crowded, imperfectly 4-ranked condition is character- 

 istic of only the proximal half of furrow. In a specimen with R 1 10 mm. the crowding 

 occupies about two-thirds length of furrow— raider more than in the slightly larger 

 specimen of magnificus. Koehler's type of magnificus (R 193 mm.) with a more extensive 

 development of the 4-ranked condition compares with the large accrescens, from St. 

 148, in which R is 235 mm. and the tube feet are 4-ranked to within 25-50 mm. of tip 



of ray. 



The characters which Koehler invokes in support of a separate genus Priamaster are : 

 (i) different form of body; (2) reduced actinal interradial areas; (3) nearly equal size of 

 upper and lower marginal plates ; (4) superomarginals not visible when one views the 

 specimen from above ; (5) the inferomarginal plates at beginning of series do not have a 

 salient keel as in true Leptychaster ; (6) the madreporic plate is visible ; (7) the ambulacral 

 furrow is much wider than in L. accrescens. 



In rebuttal it may be stated, seriatim: (i) not of generic significance; (2) not more 

 reduced than in L. kerguelenensis ; (3) a varietal character since our specimen has infero- 



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