E. S. flOODlv'IOll. 
1 14 
from the cells, by means of which they are attached to the 
surrounding structures. From each of the cell-bodies a long 
flngellum passes down the tube into the canal of the nephri- 
dium almost to the external pore. A few similar but shorter 
flagella spring also from the wall of the canal itself. Sections 
show that the lumen is inti-a-cellular, that nuclei are present 
in the wall of the duct leading to the pore, but absent in the 
fine branches. It is intei-esting to find that the solenocytes 
project freely both into the mesenchymatous spaces on the 
outside of the membrane, and into the coelom, passing through 
the coelomic epithelium. 
We may now add the Echiuroidea to the already long list 
of groups in which are found typical solenocytes. 
What may be the origin of the anterior kidney tubes of the 
adult Echiurus is still quite unknown. Obviously they are 
not derived from the larval organs, which open much farther 
forwards in front of the large paired setee. Hatschek (6) and 
Salensky (10) have given some acconnt of the development of 
the posterior so-called anal kidneys, and these appear to be 
not nephridia at all, but coelomoducts derived from the 
coelomic epithelium. The more anterior kidneys of the adult 
are probably of the same nature. I may add that I have 
found no trace of the supposed opening of the duct of the 
larval nephridium into the coelom mentioned by Salensky. 
fi’HK Actinotkooha Lakva of Phouonis. 
In a paper published in 1903 (3) I was able to show that 
the larval nej)hridia of this larva project into the hmmocoele, 
where they end blindly in bunches of solenocytes. It is 
unnecessary for me to repeat here this account, or to again 
refer to the older literature on the subject. But attention 
may be drawn to several papers since published. Cowles (1) 
and De Selys Longchamps (12) have confirmed most of my 
statements with regard to the structure of the nephridium. 
Moreover, De Sel 3 ^s and Cowles agree with Ikeda (8) as to 
the origin of the nepliridia from an ectodermal pit. But it 
