120 
SIDNEY F. HARMER. 
lopliopliore takes place with great readiness in this species of 
Phoronis. Although it is probable that this regeneration 
may be no more than the replacement of the lopliophore pre- 
viously present, there is reason to suppose that in other cases 
it indicates the occurrence of a process of asexual repro- 
duction, the regenerating lopliophore being formed, in such 
cases, at the distal end of a proximal part of the body 
separated off from the remainder by a zone of transverse 
fission. Before considering the evidence in favour of this 
view it will be convenient to notice previous observations 
bearing on this subject. 
The power of regeneration possessed by Phoronis early 
attracted the attention of observers of this animal. Dyster 
(1858, p. 251) states that “an abstracted head [of P. hip po- 
or epia] is renewed within forty-eight hours, not completely 
developed, but with a serviceable mouth and its covering- 
valve and stumpy tentacles which do their work of pro- 
viding food.” In the same year Van Beneden (1858 1 , p. 460, 
Plate, figs. 4-6, and 1858 2 , p. 18, PI. v, figs. 4-6) describes 
and figures the spontaneous loss of the lopliophore and its 
subsequent regeneration in P. gracilis. Cori (1890, 
p. 502), in describing P. psammophila, mentions the same 
phenomenon, which occurs spontaneously, although he refers 
to the belief of the fishermen of Messina that the “ heads ” 
are bitten off by small fishes. In the course of a paper 
dealing with Ccelenterates, Cerfontaine (1902, p. 262) records 
some interesting observations on P. kowalevsky i, 1 which 
occurs at Naples in a very restricted situation under a bridge 
in the “ arriere-port de Naples.” The animal forms large 
colonies in this locality, and these are found in a flourishing 
condition during a certain part of the year, namely from 
May to November. They are provided, at this period, with 
lophophores, among the tentacles of which occur numerous 
1 De Selys-Longchamps (1907, p. 173) points out that this form is 
indistinguishable on anatomical grounds from P. liippocrepia, but 
that its tubes are encrusting, while P. liippocrepia is a boring 
species. 
