Adambulacralpladerne ere store og have henimod Bug- 
furen en stump trekantet Form; deres underste Flade har 
mange smaa, mere eller mindre runde Knuder, der tjene 
til Artikulationsflader, dels for Ambulacralpiggene, dels for 
de siddende Pedicellarier. Sidefladerne ere meget brede 
og gaa noget paaskraa. 
Den inderste (ste) Adambulacralplade har en sær- 
egen Form. Indad mod Mundaabningen forlænger den sig 
og danner Tandlegemet, der bærer en sterk Tand. Til 
Siderne danner den en vingeformig Udvidning, hvis ind- 
vendige, udhulede Flade sammen med en lignende Flade fra 
den tilsvarende Iste Adambulacralplade paa den modsatte 
Side. optager Odontophoren. Den undre Flade af denne 
Adambulacralplade har to ligeløbende Rækker tætstaaende, 
runde Knuder, der ere Artikulationsflader for to Rækker 
Papiller, Fig. 4, b. 5, d, hvoraf de i den ydre Række ere 
korte, fladtrykte med en lidt afrundet Rand og slutte sig 
tæt til den indre Række, som bestaar af længere, tykkere 
og mere afstumpede Papiller. Hvor begge de Iste Adam- 
bulacralplader støde sammen paa Midten, er en temmelig 
bred Sutur. Stundom var Iste Ambulacralplades Sidepro- 
ces voxet sammen med den forlængede Del af Adambula- 
cralpladen, og da fik det et Udseende, som om begge disse 
Plader dannede Tandlegemet. 
Odontophoren, Fig. 13. 14. 15, har et yderst smalt 
Midtparti med skarpe Rande og brede Sideflader, Fig. 13, a. 
15, og fra dens øverste Del udgaa to vingeformige Processer, 
Fig, 13,0, hvis indre, hvælvede Flader optages af de før- 
beskrevne vingeformige Udvidninger paa Iste Par Adam- 
bulacralplader; den nederste Ende af Odontophoren er fri 
og støder ikke til nogen af Bugpladerne. Paa den indven- 
dige Rands øverste Del, Fig. 15, a, fæster sig den mem- 
brangse Skillevæg af et Interbrachialrum. 
Farven. 
Bleggul overalt, kun ere Randpladerne og Bugfladen 
blegere end de øvrige Dele. 
Findested. 
Station 18, et Par Exemplarer. Stat. 31, tre Exem- 
plarer. Stat. 33, et mindre Exempl. Stat. 40, et Par 
mindre Exempl. Stat. 54, et Exempl. Stat. 87, to Expl. 
Stat. 96, et lidet Exempl. Stat. 240, fem mindre Exempl. 
Stat. 248, nogle Exempl. Stat. 251, et lidet Exempl. 
Stat. 295, et Exempl. Stat. 303, et Exempl. Stat. 362, 
et Par Exemplarer. 
Den nu beskrevne Sostjerne har unegtelig nogen 
Lighed med den af Wyville Thomson beskrevne Archaster 
9 
3 
The adambulacral plates are large, and towards the 
ventral furrow, have an obtuse triangular form. Their in- 
ferior surfaces have, many small, more or less round, knobs, 
which serve as articulatory surfaces, partly, for the ambul- 
acral spines, and partly, for the sessile pedicellariæ. The 
lateral surfaces are very broad, and are somewhat, slanting. 
The inmost (1st) adambulacral plate has a peculiar 
shape. Inwards, towards the oral aperture, it becomes el- 
ongated, and forms the base of a strong tooth. It becomes, 
laterally, expanded in a wing shape, and the interior hol- 
lowed surface, in conjunction with the similar surface of 
the corresponding Ist adambulacral plate of the opposite 
side, carries the odontophore. 
The inferior surface of this adambulacral plate has, 
two parallel series of close-set round knobs, forming arti- 
culatory surfaces for the series of papillæ (figs. 4,0. 5, Å), 
of which, those im the outer row are short and flattened, and 
have a slightly rounded margin, and they close immediately 
to the inner series, consisting of longer, thicker, and blun- 
ter papille. A rather broad suture occurs, at the point 
in the middle, where both of the Ist adambulacral plates 
butt. Occasionally, the lateral process of the ambulacral 
plates is concreted with the prolongated portion of the 
adambulacral plate, and it then assumes, an appearance as 
if both of the plates formed the base for the tooth. 
The odontophore (figs. 15. 14. 15) has an extremely 
narrow mesial part, with sharply defined margins, and 
broad lateral surfaces (figs. 13, a. 15) and from its super- 
ior part proceed, the wingshaped processes (fig. 13, 0), 
whose inner convex surfaces are occupied, by the previously 
described wingshaped lateral expansions of the first pair 
of adambulacral plates. The lower extremity of the odon- 
tophore is free, and does not abut with any of the ventral 
plates. 
is secured on the superior part of the interior margin 
(fig. 15, a). 
The membranous septum of an interbrachial space, 
Colour, 
Pale yellow, over the entire starfish; the marginal 
plates and ventral surface being paler than the other parts. 
Habitat. 
Station No. 18. Å couple of specimens. 
— , ol. Three specimens. 
= , 39. A small specimen. 
— » 40. A couple of small specimens. 
— , 94. One specimen. 
= , 87. ‘Two specimens. 
— » 96. A small specimen. 
— » 240. Five small specimens. 
— , 248. A few specimens. 
— , 251. A small specimen. 
— » 295. One specimen. 
== » 903. One specimen. 
— , 362. A couple of specimens. 
The starfish which has now been described, has, 
undoubtedly, some resemblance to the Archaster vexilli- 
