REPORT ON THE ASTEROIDEA, XX1X 
Subfamily 3. PssuDARCHASTERIN®, Sladen, 1886. 
Archasteridee with a definite medio-radial line of abactinal plates, Abactinal plates 
arranged in longitudinal series parallel to the median series. Actinal intermediate plates 
well developed. Abactinal plates devoid of internal imbricating ridges. No pedi- 
cellariz. 
Genus 1. Pseudarchaster, Sladen. 
Genus 2. Aphroditaster, Sladen. 
Subfamily 4. ArcHAsTERIN», Sladen, 1886. 
Archasteride with a definite medio-radial line of abactinal plates. Abactinal plates 
in oblique transverse rows on each side of the median series. Abactinal plates with 
special internal imbricating ridges. Actinal intermediate plates aborted, or very few in 
number. Pedicellarize present. 
Genus 1. Archaster (Miiller and Troschel), emend. Sladen. 
For a Synopsis of the Subfamilies and Genera included in the Family Archasteride, 
see p. 2. 
ARCHASTERID incertx sedis. 
The following recently described genera appear to me to belong to the family Archas- 
terine, but the descriptions published do not enable me to indicate their position more 
definitely, and in some cases the reference to the family is doubtful. 
Genus Benthopecten, Verrill. 
Genus Blakiaster, Perrier. 
Genus Cheiraster, Studer. 
Genus Crenaster, Perrier. 
Genus Goniopecten, Perrier. 
Genus Pectinaster, Perrier. 
Genus Lwidiaster, Studer. 
?Genus Odontaster, Verrill. 
Remarks.—Judging from the description alone, I have great hesitation in placing 
Odontaster with the Archasteride ; it may possibly prove to be more closely allied to the 
Pentagonasteride : in any case it appears to be an annectant genus between the two 
groups. 
Family II. PorcELLANASTERID, Sladen (1883), emend. 1886. 
Phanerozonate Asterids with thin and lamelliform marginal plates, naked or covered 
only with membrane. Abactinal area covered with membrane, beset with simple spini- 
