THE ECHINODERMS OF PORTO RICO. 
By HUBERT LYMAN CLARK, 
Professor of Biology , Olivet College, Michigan. 
The following account of the echinoderms of Porto Rico is based primarily on 
the extensive collections made by the U. S. Fish Commission steamer Fish Hawk 
in January and February, 1899, comprising considerably over 1,000 specimens and 
representing 85 species. The collection of crinoids is very small, but whether this is 
due to the difficulty of dredging in those waters or to the comparative scarcity of 
that group of echinoderms around Porto Rico it is impossible for me to say. The 
collection of holothurians is also small, but in this case there is little doubt that the 
difficulty of dredging is responsible. The collections of starfishes and sea-urchins, 
though not very extensive, probably represent with a fair degree of completeness the 
littoral fauna of Porto Rico in those groups. The collection of brittle-stars is large, 
comprising more specimens and more species than all the other groups combined, 
and it is doubtless very representative, at least of the littoral fauna. 
I have also had the privilege of examining the echinoderms collected in the winter 
of 1900 near San Juan by Mr. George R. Gray. Though this collection embraces only 
22 species, it includes 1 holothurian and 1 brittle-star not in the, Fi.ft Hawk collections. 
The number of species in the following list is therefore 87, of which 3 are crinoids, 11 
asteroids (starfishes), 49 ophiuroids (brittle-stars), 13 echinoids (sea-urchins), and 11 
holothurians. Of these, 8 seem to have been heretofore undescribed and 14 others 
have their previously known range extended considerably, so that the collections add 
not a little to our knowledge of West Indian echinoderms. About 50 of the 87 species 
may be classed as “littoral” forms; that is, they may be looked for in water of less 
than 2 fathoms depth, and nearly all of them occur in much shallower water than that, 
often just below low-water mark. Judged by these collections, the echi noderm fauna 
of Porto Rico is essentially like that of the other West Indian islands, although some 
of the new forms may prove to be confined to Porto Rico alone. At present we know 
too little of the fauna of any of the islands to draw any far-reaching conclusions. 
In preparing this report two very different objects have been kept in view, but 
it is hoped that the attempt to combine them in one paper will not detract from the 
value of the work. Primarily, it is intended to present a complete report of the 
collections made by the Fisli Iia/uok , describing and figuring the new species, and 
giving a full list of the echinoderms of Porto Rico. But the attempt is also made 
to give. a brief description and account of each species, sufficient to enable anyone 
acquainted with zoolog}^ to identify them. The echinoderms are among the most 
233 
