THE ECHINODERMS OF PORTO RICO. 
259 
9. Holothuria rathbuni Lampert. (PI. 17, tigs. 2 to 10.) 
This species reaches a length of 200 mm. The body-wall contains tables and buttons with three 
pairs of holes. Occurs from Bermuda to Brazil. 
There is a small holothurian in the collection from Culebra, which I have finally decided to con- 
sider a young specimen of this species. II. rathbuni was first described by Mr. Richard Rath bun from 
specimens collected at Rio Janeiro, but he gave no name to it. In 1885 Lampert, without any further 
information, gave the species the name rathbuni. Among holothurians which I collected in Jamaica 
in 1896 and 1897, there are numerous specimens which may be referred without doubt to Mr. Rathbun’s 
species. In 1899 the New York University party collected similar specimens on the south shore of the 
Bermuda Islands. These specimens all agree in coloration, size, and calcareous parts, as well as in 
habits, with the specimens from Brazil, as described by Mr. Rathbun. The Porto Rican specimen 
before me is only 50 mm. long, and is rather spindle-shaped, tapering towards both ends. The pedicels 
are confined to the ambulacra, where they form five double rows, which are very distinct near the two 
ends, but rather indistinct at the middle. Tentacles 20 in number, small and pale. Color light gray 
with a decidedly yellow tinge ventrally, more or less distinctly marked on the interambulacra with 
purplish black. Cuvier’s organs are present, dirty green in color. There is no genital gland, which 
adds strength to the opinion that this is a young individual. It differs from adults in the arrangement 
of the pedicels, which are in them irregularly scattered. As no figures have ever been published of 
the calcareous parts of II rathbuni, it seems wise to give them in connection with this individual. 
10. Holothuria surinamensis Ludwig. 
This very common species reaches a length of about 150 mm. The body-wall is often very thin. 
It contains a few irregular rods and numerous imperfect tables which lack the disk. Occurs from 
Bermuda southward to Surinam and into the Gulf of .Mexico. About half of the holothurians collected 
by the Fish Hawk consist of this species, of which there are 40 specimens, 30 to 140 mm. in length, 
from Ponce, Boqueron Bay, San Juan, Puerto Real, and Guanica. In some the “bars” in the skin 
are numerous and very noticeable and the tables are heavy, while in others the “bars” are rather 
infrequent and the tables more delicate. 
11. Synapta lappa Muller. 
This large synapta reaches a length of 600 mm., or even more. The color varies considerably, 
from light gray to dark brown. The body- wall is thin and contains numerous “anchors and plates” 
(characteristic of the genus) and great quantities of miliary granules. It is found under rocks on 
sandy bottom in shallow water throughout the West Indies. Mr. Gray’s collection contains a single 
specimen, found under a rock near San Juan. 
Besides the species with the shield-shaped ’’ tentacles, there will doubtless be 
found along the shores of Porto Rico representatives of another family of holothu- 
rians, the Dendroclurotce. Of this family Oucumaria punctata, Ludwig' and species 
of Thyone are almost sure to occur. Of the Synaptidm , besides Synapta lappa 
Muller, Synapta vivipara (CErstedt) and Chin' data rotifera Pourtales will very 
probably be collected. Moreover, another genus of the AspidochiroUe (of which 
Holothuria is a typical genus), Mulleria , may occur. This latter genus can be easily 
recognized by the five prominent calcareous teeth in the anus. It is brown, mottled 
with darker and lighter shades, and reaches a length of 300 mm., or thereabouts. 
M. agassizii Selenka, with 25 to 30 tentacles, has been collected in Florida, Haiti, 
the Tortugas, Bimini, and Jamaica. Otccumaria punctata , which reaches a length of 
70 or 80 mm., maybe recognized by the 10 much-branched dendriform tentacles, 
the bluish-gray color, and the yellowish pedicels, which occur in double rows along 
the ambulacra but are also somewhat scattered on the rest of the body. It occurs in 
cavities within and underneath broken rocks, from Bermuda to Barbados. Thyone 
