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SIDNEY F. HARMER. 
procta and Ectoprocta alike) indicates the probable phylo- 
genetic importance of these structures in the two groups. 
Both the Molluscan foot and the Polyzoan epistome are 
ventral outgrowths of the body situated between mouth and 
anus, and with each of these organs is connected a pair of 
suboesophageal (pedal) ganglia. The foot in Gastropod 
Trochospheres (Bobretzky, No. 48) bears a striking resem- 
blance to the epistome of Loxosoma ; it forms a conspicuous 
prominence immediately behind the mouth (see fig. 106, vol. i, 
of Balfour’s ‘ Comp. Embryology’). It is separated from a 
region bearing the anus by a deep transverse groove, which on 
the supposition that the epistome represents the foot of Mol- 
lusca would correspond with the vestibular invaginations of 
the larval Loxosoma or with the median depression behind 
the epistome in the adult. 
Professor Lankester has kindly furnished me with a proof of 
his article “ Polyzoa,” shortly to appear in the ‘ Encyclopaedia 
Britannica.’ In considering the phylogeny of the class, Lan- 
kester has adopted the view that the Entoprocta do not in 
reality exhibit archaic characters, but that they have been 
derived from forms like Phoronis with a hippocrepian lopho- 
phore, a large coelom, and a dorsal flexure of the gut. There 
is, however, really no evidence that the circular Entoproctous 
lophophore is a special modification of the horse-shoe-shaped, 
and it appears to me more natural to consider it as replacing 
the larval ciliated band, which probably represents the similar 
structure in Trochospheres. My conclusions with regard to 
the surfaces of the larva are diametrically opposed to those of 
Lankester, and I must again refer to the characters of the 
nervous and excretory systems as indicating the relations of 
the Entoprocta to other animals. 
On the assumption that Loxosoma is not an archaic form, 
it is necessary to show that the complicated ontogeny of the 
Ectoprocta has been here replaced by a direct development, 
whereby the enigmatical larval organs of these forms have 
been lost. 
It appears to me, however, that the development of the 
