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SIDNEY F. HARMER. 
the bud, as one may assume the young polypide to be (Barrois 
takes the view that it is not a budding process), in this case 
occupies a position which is by no means unlike that of the 
young bud of Cyphonautes and of those of Loxosoma, 
that is to say, it occurs on the dorsal side of the ciliated ring. 
It is possible that in many Ectoprocta the dorsal organ, and 
even the foot-gland, may be completely lost at all stages of 
development, as if Barrois is correct in stating that the poly- 
pide (possibly only its tentacle sheath and the organs con- 
nected with it?) develops from the "ciliated disc,” it is 
obvious that the latter cannot entirely correspond with the 
sucker of Loxosoma, but must represent in addition part of 
the region situated more anteriorly in the latter. 
It seems to me that a consequence of the facts known with 
regard to the development of Membranipora and Tendra 
must be an inquiry as to the validity of the assumption that 
the Cheilostomata form the most modified of the groups of 
the Marine Polyzoa, a conclusion, I believe, based mainly on 
the characters of the aperture of the zocecium or "cell.” 
It is now necessary to consider the possible relationships of 
the Polyzoa with Phoronis and the Brachiopoda. 
Caldwell has stated that " the identity of the Phoronis larva 
up to the formation of the nephridia, and before the outgrowth 
of the anal region, with the Trochosphsere type of Hatschek 
is complete,” and as far as the larval characters go, I am ready 
to admit that there is probably a real affinity between Phoronis 
and the Polyzoa. From the commencement of the meta- 
morphosis of Actinotrocha, however, it seems to me that 
every step taken towards the attainment of the adult condition 
is a step away from the Polyzoa. 
The permanent nephridium of Loxosoma is the head-kidney 
which forms a provisional excretory organ in Actinotrocha 
and other Trochospheres. Thus the adult Loxosoma, in 
the absence of the " secondary body cavity ” and of the 
ciliated funnel of the nephridium, and in the retention of the 
" primary body cavity ” of the larva, has remained at a grade 
which is passed by Phoronis long before the adult condition 
