Australian Eartkirorins. 229 



In the first sefjment there are no nephridia, and in the second, 

 a thick tuft of what are apparently micronephridia take the 

 phicc of the ordinary pair. No funnel could be seen opening 

 from this mass of tubules. Behind these two segments a con- 

 spicuous pair of meganephridia is situated in each segment. 

 Throughout the body these nephridia appear to consist of tho 

 same parts [Fig. 8], though there is some variation in the 

 thickness and length of the several coils in different regions. 

 Tlie nephridia. towards the anterior end, seem to be thicker 

 walled and more closely coiled than those behind the spermi- 

 ducal glands. Tlie funnel [Fig. 8] is connected by a fine duct 

 passing through the septum to a large coiled portion [Fig. 8, 

 c.n.], averaging 3 mm. in length. One coil, the same in each 

 nephridium behind segment 18, is curiously dark in colour, 

 apparently containing pigment [Fig. 8, p. c.n.]. A fine thread 

 passes out of the coil and along the body wall, entering it 

 between the fourth and fifth seta from the ventral surface. 



Microscopic Structure. — The funnel is relatively large, and 

 is formed by columnar ciliated marginal cells which appear to 

 be twenty in number, and are arranged in a very definite way 

 in a single row. [Fig. 9, cm.] From the funnel ciliated cubic 

 cells are continued for a very short distance, and the lumen 

 surrounded by these soon passes into the usual intracellular 

 duct. 



The pigmented coil mentioned above is well seen when the 

 nephridium is mounted whole in glycerine. In section, the pig- 

 ment appears to be present in the form of granules laid down 

 in the substance of the cells lining the coil, the lumen of w^hich 

 is intracellular. [Fig. 10.] The nuclei are well seen in some 

 of the sections. [Fig. 10, nucL] Apart from the presence of 

 the pigment granules, the histology of this coil is similar to 

 that of the rest of the larger coils of the nephridia, being lined 

 by large clearly-nucleated cells. There is no well-marked mus- 

 cular duct, but its place is taken by a long intracellular straight 

 duct [Fig. 8, i.d.], which, after traversing the segment for a 

 short distance, enters the muscles and passes out through them 

 to the exterior almost directly, the external opening being very 

 small. 



