4.84, A. T. MASTERMAN. 
because it actually becomes the pharynx of the adult, and it 
appears to have a function and a relationship with the 
remainder of the alimentary canal, which is usually more 
identified with a pharynx than an cesophagus. Morgan, in 
describing early stages of the New England Tornaria, 
remarks that it first consists of a simple tube, quadrilateral 
in outline, with long cilia throughout its length. 
“The cilia on the dorsal wall of the cesophagus do not 
continue into the stomach, whilst those over the ventral side 
continue, after a slight interruption at the groove, as a 
narrow band down the anterior wall of the stomach; the 
cilia become smaller as the band runs down the wall, and 
cease about the middle of the stomach ” (p. 418). 
In the advanced larvee which I have examined the arrange- 
ment is rather more complex. The pharynx (cesophagus) is 
a conical tube with its narrow end towards the stomach. Its 
cross section 1s never quadrilateral. ‘The outline of the mouth 
itself is seen in Fig. 11 as it appears in the living animal ; 
an enlargement of the same view is shown in Fig. 16. It is 
about twice as broad as it is long (antero-posteriorly). The 
two lateral corners are pulled out into loops, whilst the 
central part is arched dorsally and ventrally. The two 
lateral grooves are not on the same level as the central 
portion, but run backwards down the lateral walls of the 
pharynx. ‘The dorsal arch of the mouth is continued back- 
wards throughout the length of the pharynx, and is lined 
with cilia (d.e.) down to the commencement of the stomach. 
The ventral portion (v.c.) is strongly ciliated throughout its 
course. Anteriorly the cilia are practically continuous with 
those of the buccal pad, and posteriorly they pass into the 
stomach. Here they expand into another large pad, the 
gastric pad (g.p.), which appears to be a specialised portion 
of the more diffusely distributed stomach-cilia described by 
Morgan. This gastric pad is a conspicuous feature of the 
living larva (cf. Figs. 11 and 15). 
The lateral grooves are continued down the walls of the 
1 Morgan, T. H., ‘Journal of Morphology,’ vol. ix. 
