den,’ ytrer sig i sm Afhandling: ,,North-American Star- 
fishes“? saaledes: ,,From an examination of the hard parts, 
it is evident that Solaster papposus and Solaster endeca 
should not be included in the same genus, having really, 
nothing in common, beyond the great number of arms. The 
accompanying descriptions will fully show my reasons for 
placing these two species in different genera.“ I hans Be- 
skrivelse over Solaster papposus og endeca kunne vi ikke 
finde en saa stor Forskjellighed, at den skulde kunne be- 
grunde deres Adskillelse i to Slægter, og vi maa i saa 
Henseende være enige med Viguier 1, at det er noget van- 
skeligt at forstaa, hvorfor denne Distinktion er gjort. 
Professor Agassiz siger selv 1 sit nysnævnte Arbeide, 
pag. 212: ,In Solaster endeca the arrangement and gene- 
ral structure of the ambulacral and interambulacral plates 
are identical with those of Crossaster — — —. The fun- 
damental difference between the genera, Crossaster and Sol- 
aster, lies in the structure of the abactinal floor. The ac- 
tinal floor between the arms is composed of small, some- 
what elongated plates, arranged in more or less regularly 
diverging rows, quite similar to those of Crossaster.“ 
Ifølge det her anførte er det fornemmelig Ryggens 
Hudskelet, som Agassiz lægger saa stor Vægt paa, at han 
lader dette være det afgjorende for Slægtens Deling. Dr. 
Viguier® har, i sin Afhandling over Asteridernes Skelet,* 
temmelig klart godtgjort, at Hudskelettet hos Solaster pap- 
posus ikke i nogen saa væsentlig Grad afviger fra det hos 
S. endeca, at nogen Deling af Slegten som Følge deraf 
skulde være nødvendig. Vore Undersøgelser bringe os til 
heri at være enige med Dr. Viguier; vistnok er det saa, 
at hos Solaster papposus ere Maskerne i Kalknettet meget 
større, end hos S. endeca; men dette kan kun komme i 
Betragtning ved Artsbestemmelsen. 
Hos Solaster affinis ere Maskerne mindre end hos 
Sol. papposus; hos Sol. furcifer ere de endnu mindre, og 
hos den af os som ny opstillede Art, Sol. glacialis, nærme 
Maskerne i Tæthed sig overordentlig meget til Sol. endeca. 
Hos Alle dannes Nettet af større eller mindre, aflange eller 
kantede Kalkstykker, der taglagte dække hinanden og danne 
kortere eller længere Bjelker, ved hvis Forbindelse Nettet 
fremkommer UMAo, ID Ides, Be 0 Gh OD Sa 
Bugfladens Interbrachialrum ere hos alle de nævnte 
Arter optagne af Kalkplader, der dels ere aflange, dels 
1 I System der Asteriden, Miller & Troschel, er Forbes's Slægts- 
navn Solaster atter optaget for papposus, og Crossaster er opført som 
Synonym. 
* Memoirs of the Museum of Comparative Zoology at Harvard 
College, Vol. 5, No. 1, pag. 98. Cambridge 1877. 
3 Anatomie comparée du squélette des stellérides par le Dr. Vi- 
guier. Archives de Zoologie expérimentale et générale. Tome 7, 
pag. 138. 1878. 
= be pg il, 
52 
it.1 thus expresses himself, in his Memoir ,North Ameri- 
can Starfishes.“? From an examination of the hard“ 
»parts, it 15 evident that Solaster papposus and Solaster en-* 
,deca should not be included in the same genus, having“ 
»really, nothing in common, beyond the great number of* 
,arms. The accompanying descriptions will fully show“ 
pmy reasons for placing these two species in different“ 
sgenera.* In his description of Solaster papposus and en- 
deca, we have been unable to find, any such difference as 
would substantiate their subdivision, and -in this respect, 
we share the opinion of Viguier, that it is somewhat dif- 
ficult to comprehend the reasons for making such a dis- 
tinction. 
At page 112 of the work just cited, Prof. Agassiz 
himself says: ,,In Solaster endeca, the arrangement and“ 
»general structure of the ambulacral and interambulaeral* 
»plates, are identical with those of Crossaster — — —* 
» The fundamental difference between the genera Crossaster“ 
sand Solaster lies in the structure of the abactinal floor.“ 
» The actinal floor between the arms is composed of small,“ 
,somewhat elongated plates, arranged in more or less reg-“ 
sularly diverging rows quite similar to those of Crossaster.“ 
According to this citation, it is the abactinal dermal 
skeleton which Agassiz lays greatest stress upon, and ad- 
opts as the decisive feature, in arriving at the generic 
subdivision. Dr. Viguier® in his Memoir on the skeleton 
of the Asteridæ* has pretty clearly established, that the 
dermal skeleton in Solaster papposus does not differ in 
such material degree from that of Solaster endeca, that any 
division of the genus should be necessary, in consequence. 
Our researches lead us to agree in this respect with Dr. 
Viguier. It is, indeed, the fact, that the meshes of the 
reticulation are much larger in Solaster papposus than in 
Solaster endeca, but this can only be accepted as material, 
in diagnosis of the species. 
In Solaster affinis, the meshes are smaller than in 
Solaster papposus; in Solaster furcifer, they are still smal- 
ler; and in the new species Solaster glacialis, which we 
have presented; the meshes, in regard to closeness, ap- 
proach in extremely marked degree, to those of Sol- 
aster endeca. In all of these, the reticulation is formed, of 
larger or smaller, oblong, and angular, calcareous ossicles, 
which laminate imbricately with each other, forming longer 
or shorter rods, which unite, and produce the reticulation 
(12 IDK, ite, 5, & 7 @ 9 6 Wil @), 
The interbrachial space of the actinal surface, is oc- 
cupied in all the above named species, by calcareous 
1 In the ,System der Asteriden*. Miller and Troschel, For- 
bes’ generic designation Solaster is again adopted for papposus, and 
Crossaster is stated to be synonymous with it. 
2» Memoirs of the Museum of Comparative Zoology at Harvard 
College Vol. 5, No. 1, pag. 98. Cambridge 1877. 
3 Anatomie comparée du squelette des stellérides par le Dr. 
Viguier. Archives de Zoologie expérimentale et générale, Tome 7, 
peg 138. — 1878. 
= I @> TR il, 
