DESCRIPTION OF GENERA AND SPECIES. 
Crass ASTEROIDEA. 
Sub-class HUASTEROIDBEA, Sladen, 1886. 
Order PHANEROZONITA, Sladen, 1886. 
Family ARCHASTERID& (Viguier, 1878), emend. Sladen, 1886. 
This family was first established by Viguier,! and comprised in his estimation the 
single genus Archaster of Miller and Troschel, to which at that date about twelve species 
were referred. Viguier, however, appears to have only had the opportunity of examining 
specimens of three or four of these, and the two species, Archaster typicus, M. and T., 
and Archaster angulatus, M. and T., were the forms taken by him as typical, and from the 
study of which the characters of the family were formulated. The genus Archaster was 
first established by Miiller and Troschel,’ for the reception of the two species named by 
them Archaster typicus and Archaster hesperus. Other species were subsequently 
referred to the same genus, though many are so widely different that latterly Archaster 
might well lay claim to be considered as the “refuge for the destitute!” It is scarcely 
exaggeration to say that most of the long-rayed Phanerozonate Asterids that could not 
immediately be ranked either as Pentagonaster on the one hand or Astropecten on the 
other, were at once set down as Archaster! Amongst the Starfishes thus disposed of 
were several deep-water forms, and a number of those recently discovered were temporarily 
relegated in like manner to Archaster at the time they were taken, and before the species 
were systematically described. In this way Archaster, and consequently the Archasteride, 
have come to be spoken of as characteristic abyssal forms. 
I have considered it desirable, for reasons explained in their proper place, to divide 
the species that have hitherto been called Archaster into several genera, and some of 
these it has been necessary, on account of their structure, to remove from the family 
Archasteridz altogether. The establishment of several new genera has likewise been 
requisite for the reception of new types. Amongst the series of allied genera that 
constitute in my classification the family Archasteride, the genus Archaster as now 
limited is in many respects a very divergent form, and is certainly not the one which I 
1 Archives de Zool. expér., 1878, t. vii. p. 235. 
2 Monatsber. d. k, Akad. d. Wiss. Berlin, April 1840, p. 104. 
(ZOOL, OHALL. EXP.—PART LI.—1887.) 1 
