not over the whole of each oval area as in the adult. Very 
fine débris is present in the intestine of one or two speci- 
mens, but in most the gut is practically empty. 
The blood-vessels are well developed, and are 
arranged as in the adult. The blood is reddish or pink 
in colour. The heart is a simple tube, dilated at its upper 
end, and contracting frequently. The two hearts do not 
beat in unison. The wall of the ventral vessel contains 
numerous spherical yellowish (some nearly colourless) 
granules, probably chlorogogenous. The flow of blood in 
the dorsal vessel is from behind forwards. 
Cells are already abundant in the ceelomic fluid. 
They are mostly oval, or spindle-shaped, and about ‘02 mm. 
long. Many of them, especially the oval cells, already 
contain yellow granules. 
The musculature is similar to that of the adult. 
Longitudinal muscles are well developed, the circular 
ones only feebly so, and the oblique muscles are very 
slender. 
There are six pairs of nephridia opening near the 
fourth to the ninth neuropodia, as in the adult. Each 
nephridium is a eurved ciliated tube (fig. 31), the 
lips at the antevior end of which are slightly everted, and 
one is larger than the other. Attached to the larger lip 
and hanging over towards the smaller are (except in the 
first nephridium) from four to eight protoplasmic pro- 
eesses* which are only visible in living specimens (fig. 52). 
They are generally of unequal length and in the lying 
specimen, 4°6 mm. long, the longest processes measured 
only ‘05 mm. Lach process is shghtly swollen about the 
middle of its length and tapers distally. It bears about 
ten moderately strong, long cilia directed backwards 
** See Goodrich, Quart. Journ. Micr. Science, p. 729-730, fig. 49, 
Vol. 43, 1900. In his specimen the processes appear to have been 
rather longer than in mine. 
