160 SIDNEY F. HAEMEE. 



No. 1 of Barrois' conclusions quoted on p. 156, appears to 

 me perfectly just. It is impossible in fact not to be struck 

 ■with the great resemblance between the solitary Pedicellina 

 shown in fig. 10 and an adult Loxosoma, and this similarity 

 is quite conspicuous even at much later stages. The obliquity 

 of the lophophore in Loxosoma is hence, on the view already 

 explained, another of the archaic features of this genus, the 

 lophophore having still a marked inclination to the " anterior " 

 side of the animal (fig, 19). 



It is unfortunate that the metamorphosis of Loxosoma, 

 which possesses a foot-gland, should be unknown, but we are 

 able to make certain inferences from the phenomena of budding. 

 Both vestibule and foot-gland originate as longitudinal groove- 

 like invaginations of the ectoderm of the " anterior " face of 

 the bud. Fig. 15 is a reproduction of a drawing from Oscar 

 Schmidt, in which the foot-gland is represented as originating 

 from the two proximal cells of the ectoderm of the " anterior " 

 side of the bud, and in which it is further seen that these cells 

 are not in the least marked off from those which are taking 

 part in the formation of the vestibule. The relations of lopho- 

 phore and foot-gland in this figure are indeed exactly those of 

 the ciliated ring in the diagram (fig. 18). 



The Metamorphosis of Pedicellina viewed in its 

 relation to the above Hypothesis. 



I have no reason to believe that the position of the ciliated 

 ring shown in fig 1 is in any way altered during the subsequent 

 metamorphosis. This structure in all probability degenerates 

 in situ. 



The ciliary apparatus of an ordinary Trochosphere is not, 

 however, constituted entirely by the prseoral circlet. In the 

 neighbourhood of the latter there occurs in Polygordius, 

 e. g., (cf. Hatschek, No. 2) a series of smaller cilia forming a 

 postoral circlet, whilst a third part of the apparatus is con- 

 stituted by " a ciliated groove running between the two ciliated 

 rings, and prolonging itself into the ciliated mouth." This 



