xl THE VOYAGE OF H.M.S. CHALLENGER. 
Remarks.—The genus Coronaster is referred by M. Perrier to the Brisingide, but I 
am unable to recognise in the description any characters to warrant that classification. I 
have therefore ventured to place it with doubt in this family. The description of Astrella 
is so very brief that I am unable to form any definite opinion as to the family to which it 
should be referred. Its position in the Asteriide can therefore only be considered pro- 
visional, until a complete description is published. The form described appears to be 
immature. Some of the characters mentioned by M. Perrier suggest at first the thought 
that the affinities of Astrella might be with the Archasteride, but the presence of the 
transverse ossicles between the adambulacral and marginal plates would seem to negative 
that view entirely. 
For a Synopsis of the Genera included in the Family Asteriide, see p. 560. 
Family X. Bristne1p#, Sars, 1875. 
Cryptozonate Asterids with numerous very elongate rays readily detachable from 
the disk. Marginal plates in part aborted altogether, elsewhere represented only by 
microscopic rudiments. Abactinal skeleton aborted or present only on the ovarial regions. 
Actinal intermediate plates altogether absent. Long lateral spinelets. Spinelets in sheaths 
crowded with pedicellariz. No interbrachial septa. 
Genus 1. Labidiaster, Liitken. 
Genus 2. Odinia, Perrier. 
Genus 3. Brisinga, Asbjornsen. 
Genus 4. Freyella, Perrier. 
Genus 5. Colpaster, n. gen. 
? Genus 6. Brisingaster, de Loriol. 
Genus 7. Hymenodiscus, Perrier. 
?Genus 8. Gymnobrisinga, Studer. 
Remarks.—I feel much doubt as to the generic validity of the three last-mentioned 
genera. J have therefore placed a query before each of them, pending the establishment 
of their independence as genera distinct from Brisinga. 
For a Synopsis of the Genera included in the Family Brisingide, see p. 589. 
The following Synopsis of the principal divisions of the Sub-class will bring the classifi- 
cation of the group into a compact form; it will also be useful in showing negative and 
antithetical characters not included in the foregoing diagnoses :— 
Synopsis of the Orders and Families of the Sub-class EUASTEROIDEA. 
I. Marginal plates large and highly developed in the adult. Papule restricted 
to the abactinal area, circumscribed by the supero-marginal plates. 
Ambulacral plates well spaced and usually broad. Actinostomial ring 
