76 PORCELLANASTERIDAE. 
named and described by him. Of the other nine species, all but one were taken 
by the ArBaTrross Expedition of 1891. 
Half of the deep-water species described as new belong to the Brisingidae, 
while a fifth member of the family, in this collection, was hitherto known only 
from the Atlantic Ocean. These facts illustrate well how characteristic of the 
deep-water fauna the Brisingidae are and how little that fauna is as yet known. 
It is worthy of note that of the more than a dozen species of Brisingidae now 
known from the Pacific, not one is in the present collection. 
With the increasing knowledge of the deep-sea fauna, several genera of 
sea-stars have been enlarged by numerous species until it is by no means easy 
to determine the various forms assigned to them. I have therefore attempted 
the revision of Hymenaster and Zoroaster. As the latter genus includes the 
bulk of the Zoroasteridae, the revision is extended to include the other genera 
and species thereof. Artificial keys to the species which seem entitled to recogni- 
tion are included. Complete lists of the species proposed up to the present 
time, in these genera, with the necessary bibliographical references, are also 
given. 
SYSTEMATIC ACCOUNT. 
PORCELLANASTERIDAE. 
Eremicaster pacificus. 
Porcellanaster pacificus Lupwie, 1905. Mem. M. C. Z., 32, p. 89. 
Eremicaster pacificus Fisaer, 1907. Zool. Anz., 32, p. 14. 
These specimens, in which R = 15 and 22 mm., are not peculiar in any 
way, but agree well with the original material from the Panamic region. I 
fully agree with Fisher, in dissent from Ludwig, that the number of cribriform 
organs is a more important, and also a more available, generic character than the 
presence or absence of the segmental papillae. The bathymetrical range is 
considerably increased by the present record and the geographical range is 
extended to the south about 300 miles. 
Station 4647. Eastern Tropical Pacific, 4° 33’ S., 87° 42’ 30” W., 2,005 fms. Bott. temp. 35.5°. Lt. gy. 
and br. glob. oz. 
Station 4649. Eastern Tropical Pacific, 5° 17’ S., 85° 19’ 30” W., 2,235 fms. Bott. temp. 35.4°. Fne. 
stky. gy. m. 
Two specimens. 
Eremicaster tenebrarius. 
Porcellanaster (Eremicaster) tenebrarius Fisaer, 1905 (10 June). Bull. U. S. Bur. Fish., 24, p. 293. 
Porcellanaster waltharii Lupwie, 1905 (July). Mem. M. C. Z., 32, p. 92. 
Eremicaster tenebrarius Lupwie, 1907. Zool. Anz., 31, p. 318. 
