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E. RAY LANKESTER. 
filled with blood-lymph (Blut-haltende Raum of Schneider). 
Their exact shape and extent in each myotome requires further 
careful study by means of a series of sections, since they are 
liable to distortion by osmotic action. 
In the first three or four myotomes, which are traversed in 
transverse sections in the neighbourhood of the eyespot and 
olfactory pit, it appears to me that the myocoel cavities are 
permanently preserved, and that the spaces as seen in 
PI. XXXVI A, figs. 3, 4, 5, are not artifact but natural. The 
myocoel has, in fact, never been obliterated by the adhesion of 
its opposite walls. 
The Atrio-ccelomic Funnels or Brown Canals. — These struc- 
tures, which I discovered and described in 1874, are a pair of 
short wide funnels placed in the 27th myotome, right and left, 
at that region where the pharynx narrows to form intestine. 
The wider end of the funnel is open to the atrium, the narrower 
end is within the dorso-pharyngeal coelom, and the axis of the 
funnel is parallel with the long axis of the body (see PI. XXXV, 
fig. 1). It is difficult to decide whether the narrow end is 
actually perforate, but I am inclined to think that it is. 
The funnels are lined internally by the pigmented epithelium 
which characterises the atrial wall. Each funnel adheres by 
one side to the roof of the dorso-pharyngeal coelom, as shown 
in the transverse section, PI. XXXV, fig. 2. The wall of the 
funnel is formed by a firm connective tissue with nuclei in 
addition to the lining layer of pigmented epithelium. The 
funnels always exhibit longitudinal folds as though they were 
capable of dilatation. 
It depends on the size of the Amphioxus whether these 
funnels are met with in sections with many bars to the pharynx, 
or in sections where the bars and slits are few in number and 
extent, and the pharynx reduced in volume. Probably in quite 
young Amphioxus the atrio-ccelomic funnels do not occur in the 
same vertical plane as any of the gill-slits, but as growth goes 
on the pharynx extends farther back, carrying with it the wide 
mouths of the funnels, the pointed extremities of which remain 
in the 27th myotome. Thus in a full-grown specimen a 
