60 Papers from the Department of Marine Biology. 
Of these, A. palmeri is recorded from rather deep water from off 
Barbados, but none of the others is known from east or south of St. 
Thomas. The mud-loving Amphioplus abditus, ranging as far north 
as Woods Hole, Massachusetts, has not been found in the West Indies 
proper but occurs on the Florida coast and at the Tortugas. The 
only known stations for A. kukenthali are the Tortugas and St. Thomas. 
I did not find it at Tortugas and it is quite possible that it is not 
really a littoral species in the strict sense. The same remark is appli- 
cable to Ophionephthyslimicola, whichI dredged at the Tortugas, while 
St. Thomas is the type-locality. The well-marked and easily recog- 
nized Ophiothrix lineata is known only from Florida and the Tortugas, 
a remarkably restricted range for an Ophiothrix. The very rare 
Ophionereis olivacea is known from only two specimens, one from 
Porto Rico and one from Key West. 
ECHINOIDEA. SEA-URCHINS. 
The littoral echini of the West Indies are not numerous so far as 
species are concerned, but in number of individuals they are often 
excessively abundant. On and about the coral reefs, the dreaded 
poisonous “black sea-egg”’ (Centrechinus antillarum) is common and 
on certain areas it is so numerous that a person can scarcely move 
about without touching one. On many reefs the boring urchin (Kchi- 
nometra lucunter) occurs actually by the thousands, and it is almost 
always common. On suitable grassy bottoms the “‘white sea-egg”’ 
(Tripneustes esculenta) is very common, and in similar localities 
Lytechinus variegatus may be so abundant that one can not walk on 
the bottom without crushing them under foot. Although Eucidaris 
tribuloides is often uncommon and hard to find, occasionally it occurs 
in great numbers and may be gathered literally by the bushel. These 
5 urchins may be expected anywhere in the West Indian region in 
considerable numbers, if the bottom and water are suitable. None 
of the other echini in the following list are common except locally, 
but any one of them may prove abundant if a particular locality is 
suitable. Thus I have neyer found Clypeaster rosaceus common until 
1917, when it proved to be abundant on the reef-flats at Bush and 
Bird Keys, Tortugas. 
The following 18 species are the littoral sea-urchins of the West 
Indian region: 
Eucidaris tribuloides (Lamarck). Encope emarginata (Leske). 
Centrechinus antillarum (Philippi). michelini (Agassiz). 
Arbacia punctulata (Lamarck). Mellita quinquiesperforata (Leske). 
Lytechinus variegatus (Leske). sexiesperforata (Leske). 
Tripneustes esculentus (Leske). Echinoneus cyclostomus (Leske). 
Kchinometra lucunter (L.). Moira atropos (Lamarck). 
viridis A. Agassiz. Plagiobrissus grandis (Gmelin). 
Clypeaster rosaceus (L.). Meoma ventricosa (Lamarck). 
subdepressus (Gray). Brissus brissus Leske. 
