MUSEUM OF COMPARATIVE ZOOLOGY. 271 
Annelids make up the greater part of this collection, Of other worms 
the Nemertine are represented by isolated fragments which do not ad- 
mit of closer detailed description or identification; they are mainly 
littoral forms from Key West, from No. 5, and from * Sigsbee" No. 9, 
and off Havana 175 fathoms; none from the deep-sea stations. One 
single species of Sábitta found off Havana in 480 fathoms (Sigsbee) is of 
course not to be ascribed to that depth, but was undoubtedly brought 
up in the net by mere chance. 
lephyreans are represented in the collection by Sternaspis, Sipunculus, 
Aspidosiphon, and Phascolosoma : Sipunculus littoral from Bahia Honda, 
Sternaspis sp. from a depth of 158 fathoms, Aspidosiphon from 190 
fathoms (No. 23), while many still undetermined species of Phascolo- 
soma are littoral, and extend as far as the greatest depth here recorded, 
one species of Phascolosoma having indeed been brought up in a Dento- 
lium shell from a depth of 1568 fathoms. 
Although so numerous, these worms have but a slight significance as 
compared with the Chztopods of the collection, The occurrence of 
Chetopods in certain localities where the animals themselves are not 
found, may be inferred by the presence of their tubes. Yet such a 
conclusion is not. always admissible without further evidence; at least 
only when the individual worm builds his tube in so characteristic 
a way that there is no possibility of mistaking it for that of other 
Annelids.* When no foreign material is used in the construction of the 
tube except mud consolidated by the secretions of the worm, the tubes 
of very different species of worms may have a great similarity among 
themselves; when, on the contrary, various foreign materials are cemented 
in the tubes, such marked peculiarities may occur in their choice and 
application that from a fragment of the tube the builder can be inferred 
with as much certainty as the snail from the form of his house; the 
form of the tubes may even be so peculiar that there is no danger of 
mistaking them for other tubes. Examples of this kind occur in the 
present collection, especially in the Eunicidæ, but also in the Maldanide, 
Sabellidw, and Serpulide. In determining the distribution of the 
worms, the data furnished by the tubes must always be used with great 
caution; for it must be remembered that uninhabited tubes may be 
carried away by currents; in such instances they would usually be 
* Several times I found tubes in the Hassler collection which from their whole ap- 
pearance I should have taken for worm-cases ; but the inhabitant was a Crustacean 
(Amphipod) I cannot decide whether in this case the occupant of the tube was also 
its builder. 
