Endelig skulle vi nu beskjæftige os med den af Pro- 
fessor Verrill nydannede Slægt Lophaster for Solaster fur- 
cifer, Diben og Koren. 
Til Begrundelse af Slægtens Dannelse udtrykker 
Verrill sig saaledes:  ,,This species differs so widely 
from Solaster m the structure of the skeleton, and the 
small development of the disk, as to require the etab- 
lishment of a new genus for this type. It is specially 
distinguished by the highly developed skeleton of the under 
side; differentiated marginal plates; and prominently retic- 
ulated dorsal plates.“! Prof. Jeffrey Bell er ikke langt- 
fra at antage, at Slægten Lophaster er vel begrundet, idet 
han lægger særdeles megen Veet paa de ,differentiated 
marginal plates, one dorso-marginal and one ventro-marg- 
inal.“ Vi have tidligere indrommet, at Randpladerne 
spille en betydelig- Rolle i Slegtskaraktererne, uden at vi 
have kunnet erkjende, at de ere afejorende. Verrill siger, 
at Solaster furcifer adskiller sig saa overordentlig fra Sleg- 
ten Solaster i Skelettets Bygning og i den lidet udviklede 
Skive, at en ny Slægt maa dannes for den; det er fornem- 
melig det stærkt udviklede Skelet paa Bugfladen, de diffe- 
rentserede Randplader og de iøimefaldende, retikulerede 
Rygplader, som bestemme den nye Slægts Dannelse. Hvad 
nu Skivens Størrelse betræffer i Forhold til Armene, saa 
varierer dette ganske betydeligt og kommer kun lidet i 
Betragtning ved Slægtsbestemmelsen; anderledes forholder 
det sig med Skeletbygningen. Vi skulle først omtale Hud- 
skelettet. 
Rygfladens Hudskelet hos Sol. furcifer dannes af et 
temmelig tætmasket Kalknet, Tab. IX, Fig. 9, a, b, der 
fremkommer derved, at smaa kors- eller x-formede Kalk- 
plader lægge sine Udløbere paa hverandre; imellem Ma- 
skerne sees en eller flere Tentakelporer, alt eftersom Ma- 
sken er liden eller stor. Omtrent den samme Anordning 
finder man hos Sol. endeca, men endnu mere ensartet hos 
Sol. glacialis, hvor kun Forskjellen er den, at de enkelte 
Kalkstykker ere noget stærkere byggede og have noget kor- 
tere Udløbere, hvorved Maskerne blive noget mindre, Tab. 
IX, Fig. 5, b, c, end hos Sol. furcifer. 
Bugfladens Hudskelet, Tab. IX, Fig. 9, d, som især 
fremtræder 1 Interbrachialrummene, skulde, efter Ver- 
rill, være høiere udviklet hos Sol. furcifer; men heri kunne 
Bugfladens Kalkplader hos Sol. fur- 
cifer ere mere eller mindre korsformede med korte Arme, 
der vel taglagt ligge paa hverandre, men som dog efterla- 
der smaa, nøgne Rum, imedens Kalkpladerne hos Sol. gla- 
Gs, Wal, IDX, Mie, 5, å, 
vi ikke være enige. 
der have næsten Korsformen, 
1 Fauna of North 
The Amer. Journal of science and arts. 
DA, 
Notice of recent additions to the Marine 
America. by A. E. Verrill. 
3rd Ser. Vol. X VI, pag. 
56 
Finally, we shall now proceed to consider the new genus 
Lophaster formed by Prof. Verrill, instead of Solaster fur- 
cifer, Diiben and Koren. 
In confirmation of the reasons for the formation of 
the genus, Verrill expresses himself thus: ,,This species“ 
differs so widely from Solaster, in the structure of the“ 
»skeleton, and the small development of the disk, as to“ 
»require the establishment of a new genus for this type.“ 
pt is specially distinguished by the highly developed skel-* 
seton of the under side; differentiated marginal plates; and“ 
»prominently reticulated dorsal plates.“! Professor Jeffrey 
Bell almost admits that the genus Lophaster is well based, 
as he lays particular stress on the ,,differentiated marginal“ 
»plates, one dorso-marginal and one ventro-marginal.“ We 
have already admitted, that the marginal plates play a 
prominent part in determining generic character, but we 
cannot, however, admit, that they are absolutely decisive in 
the matter. Verrill states, that Solaster furcifer differs so 
very much from the genus Solaster in regard to the con- 
struction of its skeleton, and in its slightly developed disk, 
that a new genus must be formed for it; and, it is prin- 
cipally, the strongly developed skeleton of the actinal floor; 
the differentiated marginal plates; and the prominent, ret- 
iculated dorsal plates, which decide the formation of the 
As far as regards the dimensions of the disk 
in proportion to the rays; this varies quite considerably, 
but is a small matter for consideration in deciding the 
new genus. 
genus; the case is very different, however, when the construc- 
tion of the skeleton is concerned. We shall first speak 
of the dermal skeleton. 
The abactinal dermal skeleton in Solaster furcifer, is 
formed of a rather close-meshed calcareous reticulation, 
(Pl. IX, fig. 9, a, b), produced by small X or crucial 
formed calcareous plates laying their projections upon each 
other. One or more tentacular pores are visible between 
the meshes, the number varying, according to the greater 
or smaller size of the meshes. A nearly similar arrange- 
ment is found in Solaster endeca, but still more similar 
in Solaster glacialis, where, the only difference is, that the 
individual calcareous ossicles are somewhat stronger con- 
structed, and have somewhat shorter projections, causing 
the meshes to be somewhat smaller (Pl. IX, fig. 5, b, c) 
than in Solaster furcifer. 
The abactinal dermal skeleton (Pl. IX, fig. 9, d), is 
specially prominent in the interbrachial spaces, and accord- 
ing to Verrill, it is more highly developed im Solaster fur- 
cifer; but we cannot share his opinion in regard to this. 
The calcareous plates of the actinal surface in Solaster 
furcifer, are more or less crucial, with short arms, which, 
lie upon each other well imbricated, but still leaving 
small bare spaces; whilst, the calcareous plates in Solaster 
glacialis (Pl. IX, fig. 5,d), which are also crucial, as well 
1 Notice of recent additions to the Marine Fauna’ of North 
America by A. E. Verrill. The Amer. Journal of Science and Arts 
3rd Ser. Vol. XVI, pag. 214. 
