68 Papers from the Department of Marine Biology. 
fauna, however, just two-thirds (66 per cent) occurs at Porto Rico, 
while of the Tobagoan fauna only a little more than half (53 per cent) 
is found there. 
Of the 54 species, 2 are as yet known only from Porto Rico; 29 are 
common throughout the tropical Atlantic and 11 others are distinct- 
ively West Indian; 4 are tropicopolitan and 7 have a northern range; 
only 1 can be considered representative of a southern fauna. The 
number of sea-stars known from Porto Rico is exceptionally large, 
nearly one-fifth of the echinoderms belonging in that class, whereas 
only 12 per cent of the entire West Indian list is made up of sea-stars. 
ST. THOMAS. 
The United States Virgin Islands, so long known as the Danish 
West Indies, are classic ground for the student of echinoderms, as a 
very large proportion of the West Indian species were first recorded 
from there, thanks to the industry and great abilities of the celebrated 
Danish zodlogist, Liitken. In the present paper, I have not attempted 
to keep separate the records from the different islands, but have 
included them all under ‘‘St. Thomas,’’ since the name Danish West 
Indies is no longer correct and the recently coined official name for 
the group is also open to misunderstanding. 
None of the 56 species here listed from St. Thomas is endemic, but 
on the other hand 6 are tropicopolitan. There are 28 tropical Atlantic 
and 13 distinctly West Indian forms. The remaining 8 species all 
have northern affiliations. There are 44 species which occur in Porto 
Rico, or 81 per cent of that island’s fauna; 47 which are found in 
Jamaica, 75 per cent of that fauna; 27 which are known at Bermuda, 
64 per cent of that fauna; 48 which occur at the Tortugas, 63 per cent 
of that fauna; and only 38 which are found at Tobago, just 60 per 
cent of that fauna. 
TOBAGO. 
The echinoderm fauna of Tobago is largely confined to the vicinity 
of Pigeon Point on the southwestern part of the island, where extensive 
coral reefs protect the shallow waters of Buccoo Bay. Although we 
made brief visits to several points on the southeastern and northeastern 
sides of the island, we found very few echinoderms indeed in those 
places. But in Buccoo Bay and on Buccoo Reef, there is an exceed- 
ingly rich fauna, especially of brittle-stars, which constitute nearly 
60 per cent of it. 
The most notable member of this fauna is the comatulid, T'ropio- 
metra carinata, & conspicuous representative of a southern fauna, 
common on the coast of Brazil. Two other representatives are note- 
worthy—the little bright rose-colored holothurian Psolidium braail- 
iense and the handsome brittle-star Ophioderma januarwi. The latter 
is apparently rare at Tobago, but a number of specimens of Psolidium 
were taken, though all are very small. 
