30 BULLETIN OF THE 
At a later stage smaller bundles of muscles arise successively toward 
the neck. These muscles are free from the body wall at their middle 
region. They do not usually pass through the coolom in a diameter of 
the branch, however, but rarely subtend as chords an are of more than 
120°. As Braem supposed, such muscles, although arising later than 
the most proximal pair, originate in a similar manner to them (Plate 
VI. Fig. 55). The mesoderm is very thin at the region at which they 
are first seen, and they are quickly discerned by their larger nuclei 
and prominent cell body. At a later stage they have grown much 
longer, and become freed from the body wall at their middle part. 
As is well known, there are two funiculi in Paludicella, called by 
Allman respectively anterior (nearer the atrial opening) and posterior. 
The origin of the funiculi of Paludicella was observed by Dumortier 
et van Beneden as long ago as 1850. They say (p. 54), “La couche 
muqueuse une fois formée s'étend rapidement dans l’interieur et touche 
bientöt par son extrémité inférieure les parois opposées de la loge. 
Les cellules muqueuses dont le tout est encore composé contractent de 
Padhérence dans cet endroit, et c’est ce qui donne naissance au muscle 
rétracteur de Vestomac [= funiculi].” Allman (56, p. 36, Plate XI. 
Figs. 7-9) also describes and figures very clearly and correctly this pro- 
cess, and Braem (’90, p. 127) has recently confirmed their observations. 
It is perhaps unnecessary to redescribe the more evident part of 
this process, the contact of the polypide with the abatrial wall of the 
branch. The mesoderm of the bud comes into contact with that of 
the body wall, the cells of each of the two layers become attached to the 
other, and by the withdrawal of the polypide the attachment persists 
at two points forming a long drawn out string of tissue. Figures 36° 
and 38 (Plate IV.) are contributions to a knowledge of the finer details 
of this process. Apparently the upper funiculus is developed earlier 
than the lower, as I have always found it longer at about this stage. 
The lower funiculus at present consists of only the two mesodermal 
layers of body wall and polypide intimately united. The funiculus 
itself consists of a cord several cells thick ; but I believe these oer- 
tainly to be derived from the mesoderm only. Very early some of 
these cells show an appearance of highly refractive and deeply staining 
fibres, which I interpret as muscular differentiation (Plate IV. Fig. 38, 
fun. su.), 80 that the funiculi must be regarded as partly muscular 
in function. As in Phylactolemata, these fibres lie near the axis of the 
funiculus. Braem (90, pp. 66, 67,) has demonstrated that the museular 
fibres of the funiculus of Plumatella pass directly into the muscularis 
