ON A LARVAL ACTINTAN PARASITIC IN A RHIZOSTOME. 225 
always be detected, which are larger and carry more secon- 
dary lobes than the remainder. The basal lobe forms a 
kind of lid or operculum to the siplionoglyph.” An original 
observation which I have made is that, when the larva is 
attached by the oesophageal folds, it is through the conchula 
that a constant stream of fluid bearing food particles goes to 
the enteron. This fact I have made out by studying living 
larvm which were still attached to the gut-wall of a Rhizo- 
stome. Correlated with the function of the conchula is the 
Text-fig. 2. 
Drawing of the oesophageal surface of a living larval form of 
Peachia liilli (x 2). The nature and markings of the 
tentacles are shown and the character of the oesophageal 
lobes. The conchula (C.) is seen to consist of a basal and two 
lateral lobes, the latter being borne by the lips of the siplio- 
noglyph (S.I.), which are in contact near the periphery but 
slightly separated near the centre. 
presence of a large number of pores in the physa. These 
pores were mentioned by Haddon ( 6 ) as occurring in 
P. hastata and included in his definition of the genus 
Peachia ( 7 ). They were noted by Miss Wilsmore ( 3 ) in 
sections and described by her so far as her material per- 
mitted. They are placed in the twelve external grooves of 
the physa, which, however, is not marked off from the scapus 
except in extreme contraction. There are generally twenty 
pores in each row arranged somewhat irregularly (Text-fig. 3). 
There is no central pore. 
