allied to Rhabdopleura. 347 
both in Loxosoma and Cephalodiscus bear other buds, but be- 
cause the position of the large ova in the latter cannot be 
confounded in any respect with the buds either in their early 
or subsequent stages. 
No differentiation was noticed in regard to sexes; and there 
seems to be no dimorphism of the zooids, asin Prof. Ehlers’s 
remarkable burrowing form (Hypophorella expansa*). No- 
thing is more striking, however, than the profusion of buds 
and the abundance of ova, one of the chief ends of the species 
apparently being propagation. The chambers of the ccence- 
cium are loaded with the large ova; and almost every adult 
bears one or more buds attached near the tip of the pedicle. 
The early buds consist of minute and somewhat pale clavate 
or pyriform bodies attached by the narrow end to the pedicle. 
They are situated either on or near the tip. Very soon the 
pedicle is differentiated from the disk, the young animal con- 
sisting of a large, flat, and somewhat thick disk and a short, 
broad, and sometimes crenate pedicle attached to the parent. 
The disk is shield-shaped, broader distally than proximally. 
Two ovoid opaque thickenings are observed dorsally. The 
hypoderm of the bud resembles that of the adult. At this 
stage no trace of the tentacular plumes exists. 
As development proceeds the anterior or disk-bearing region 
of the body increases much more in proportion than the poste- 
rior. The disk is rapidly enlarged, and shows traces of the 
broad arch of pigment anteriorly and the reddish band poste- 
riorly, as well as the two median elevations on the ventral 
surface. ‘The posterior moiety of the disk is especially large. 
Moreover the body superiorly begins to project outward, and 
first one or two and then four or five rounded papille indicate 
the commencement of the tentacular plumes. ‘These papille 
form a slightly curved row in front of the dorsal projection of 
the body. 
In the next stage the disk is almost completely formed, 
though of smaller size and thicker than in the adult. The 
pigment bands are well developed. So little has the pedicle 
advanced, that the free posterior margin of the disk almost 
touches the pedicle of the parent to which the bud is attached. 
The anterior dorsal projection of the body has greatly in- 
creased, forming a large rounded boss. ‘The tentacular or 
branchial plumes are now more numerous, and form an irregu- 
lar and prominent double row from side to side above the 
disk. The short pedicle almost immediately follows the an- 
terior dorsal projection of the body ; and as a peculiar bending 
of the latter has now taken place, the tip of the pedicle hardly 
* Abhandl, der koniglichen Gesellschaft der Wiss. zu Gottingen, 1876. 
