BARBADOS-ANTIGUA EXPEDITION 99 
portion long enough to cover the length of their own bodies. 
I sent some of them to the National Museum, along with other 
specimens collected at the same time, for identification. In one 
bottle I sent also a portion of the worm-like tubes in the sponge. 
This has not been returned and I am not at all sure that the 
annelid is Laodice furcata, as indicated above. The tubes were 
not only forked, but much twisted and tied in knots as it were, 
making it still more difficult to secure the worms. 
Cirratulus melanocanthus is a tube-dwelling worm with a large 
tuft of exceedingly slender tentacles, also collected off Lord’s 
Castle. A form which I take to be a sipunculid, is often found 
imbedded in hard coral rock in cavities in which it fits as into 
a mould. It is short, ovoid in shape, with very hard leath- 
ery integument, transversely wrinkled in some cases, longi- 
tudinally in others.. The larger, posterior portion of the body 
is light buffy in color, with perfectly rounded brownish dots in 
the center of which are light nodules, the whole resembling the 
small tubercles of certain sea-urchins. On the anterior, darker 
and more slender part, there are larger and more closely aggre- 
gated rough tuberculations. This is also true of the larger, 
more abruptly rounded posterior part of the animal. The 
proboscis is completely introverted in retraction; its extensibil- 
ity is, however, quite remarkable, and when extended it shows a 
terminal crown of light-colored brown tentacles; posterior to 
which are two annular sharply raised ridges or collars. The 
proboscis is also furnished with numerous denticles or horny 
nodules of brown color. The body wall is remarkably tough in 
texture, like strong parchment, and the body cavity contains a 
curious structure that I have not seen elsewhere among worms; 
but that reminds one of the ossicles in the ‘‘lantern’’ of cer- 
tain holothurians. There are three hard broad horn-lke plates 
placed horizontally and making a partial partition in the body 
cavity. These are fastened firmly to the adjacent body wall 
and appear to furnish attachment to strong muscles employed 
in the retraction of the introvert. This worm appears to be 
allied to Phascolosoma of northern waters. One specimen which 
may belong to a different species, is characterized by having nu- 
merous transverse rows of microscopic hooklets on the proboscis, 
and some distance behind the tentacle crown, all of the hooklets 
