439 
of Edinburgh , Session 1868-69. 
veloped along their attached side, and to this rod the polypides 
are connected from distance to distance each by a flexible cord or 
funiculus. 
The polypides are hippocrepian, and each carries a shield-like 
process on the hsemal side of its lophophore external to the ten- 
tacular series. 
The development of the bud was traced, and it was shown that 
in an early stage the polypide is included between two fleshy 
plates, which are placed, one on the right and the other on the left 
side, and are united to one another along a portion of their circum- 
ference, while they are disunited along the rest. For some time the 
two plates keep pace with the general development of the bud, but 
ultimately they cease to increase in size, and then remain as the 
shield- like process carried by the lophophore of the adult polyzoon. 
The author regarded these plates as representing the right and 
left lobes of the mantle in a Lamellibranchite mollusc, from which 
it followed that the relations of the Polyzoa are more intimate 
with the Lamellibranchiata than with the Brachiopoda, with which 
of late years they had been associated, but whose mantle lobes lie 
dorsally and ventrally, instead of lying right and left, as in the 
Lamellibranchiata. The lophophore of the Polyzoa was considered 
by the author as having its representative in the labial palps of the 
Lamellibranchiata. 
The following were given as the generic and specific diagnosis of 
the new Polyzoon 
Genus Riiabdopleura, Allman. 
Ccenceicum consisting of a branched adherent membranous tube, 
in whose walls along their adherent side a rigid chitinous rod 
extends, and whose branches terminate each in a free open tube 
through which the polypide emerges. 
Lophophore hippocrepial, with a shield-like process on the haemal 
side of the tentacles. Polypides connected to the chitinous rod 
by a flexible cord or funiculus. 
Rhabdopleura Normani , Allman. 
Coencecium sub-alternately branched, delicate, transparent, and 
colourless ; free portion of the ccenoecial tubes of the same diameter 
as the adherent portion, and very distinctly and regularly annulated. 
3 L 
VOL. VI. 
