THE ANATOMY OF PHORONIS AUSTRALIS. 141 
he became aware of the existence of the second funnel, shortly 
after the publication of his paper. 
I cannot agree with him as to the relations, as shown in his 
diagram (4, p. 383), between the position of the external 
opening and the mesentery. He places the external aperture 
on the wall of the lateral (cesophageal) chamber, and the 
internal opening, 1. e. the large funnel, in the rectal chamber. 
With regard to the position of the latter there is, of course, 
no question; but I believe it can be readily seen that the 
external aperture lies on the outer wall of the rectal chamber, 
the internal apertures being one on each side of the lateral 
mesentery. 
The whole of the lumen is lined by ciliated cells: the cells 
lining the duct being nearly cubical (fig. 28) ; those lining the 
funnel being rather taller, and the cilia considerably longer 
(fig. 29). 
I could find no solid concretions in the cells of the nephri- 
dium, but some of the cells appear secretory, and have clear 
unstained contents. No blood-vessels are present on the wall 
of the nephridium, but a nerve passes along its wall. 
The Gonads.—Phoronis is hermaphrodite ; the two re- 
productive elements being formed close together in the aboral 
region of the body, as was first described and figured by 
Kowalevsky (15, fig. 9). 
When the animal is opened, a large whitish mass is seen 
lying on one (the left) side of the stomach, which it nearly 
completely hides (fig. 24). This mass surrounds the efferent 
blood-vessel, and consists of ova on one side and spermatozoa 
on the other. 
The efferent trunk, which lies in the left cesophageal 
chamber, has throughout its course numerous small branching 
cecal offshoots: in this particular region the celomic epithe- 
lium covering these vascular cca, becomes modified to form 
ova and sperm-mother-cells (fig. 383). Probably the cells 
become mature at different seasons of the year, for I have been 
unable to find, in my sections, any fully- formed spermatozoa ; 
5 «Structure and Development of Phoronis.” 
