1873.] 347 [Morse. 
in the perivisceral cavity. In all these cases the eggs are discharged 
freely into this cavity, and there float in the perivisceral fluid until 
they are discharged from the body. , 
If we now consider the ducts by which these products in the 
Brachiopoda find egress from the body, we shall find a startling iden- 
tity of structure with similar parts in the Annelida. 
In all worms, with few exceptions, these ducts assume the shape of 
tubes, bilaterally disposed, suspended in the perivisceral cavity by 
delicate membranes, and communicating with this cavity by flaring 
orifices, which are strongly ciliated, as well as the tubes them- 
selves, to their external orifices; the ciliary action always directing 
the currents out of the body. ‘These are the segmental organs, or 
oviducts. 
According to Clapareéde, the segmental organs in the Annelida 
present only very simple modifications of a very constant type. Ina 
large number of worms, these segmental organs are repeated many 
times, a few of them only modified as oviducts. In other worms they 
are reduced in number; in Branchiobdella, according to Dorner, to 
two pair; in Terebella parvula to three pair, as Dr. Williams states. 
In Protula,! Spirorbis, Sabella, and allied forms, a single pair of seg- 
mental organs, modified as tubiparous glands are found in the anterior 
part of the thorax. 
In Phoronis the ovarian openings are reduced to a single pair, and 
these open at the extreme anterior surface of the body between the 
arms, from which the eggs escape after having been discharged from 
the ovary into the perivisceral cavity. In the Brachiopoda the ducts, 
by which the generative products find egress from the body must be 
described in precisely the same terms as those used in describing the 
segmental organs of the Annelids. The ducts assuming the shape of 
tubes, bilaterally disposed, suspended freely in the perivisceral cavity 
by delicate membranes, and communicating with this cavity by flar- 
1 Tk. tubiparous glands, according to Claparéde, represent modified segmental 
organs. In Protula (Salmacina) edificatrix, Claparéde represents the tubiparous 
glands as opening by a common pore, as in Spirorbis. A careful study made by me 
of a species of Protula (probably P. Dysteri Huxley) at Eastport, Me., showed the 
wide separation of these glands, and the fact that they opened by two distinct 
pores, thus bringing them nearer the Sabellarians. 
The minute structure of these glands, revealed a sinuous line rapidly undulating, 
following the inner outline of the gland. This appearance appeared due to ciliary 
action. Other features were presented by these curious organs, which led me to 
believe that other functions were performed by them beside that of secreting the 
tube. Their relations to the segmental organs were unquestionable, however. 
