(vo) 



Each of tne excretory processes is tip-eci by a body, the 

 distal end of whicii is drawn on.t into a shari. pointea process. 

 I have been unable to see tiie outline of more tnaii one cell in 

 the body, Sornotimes it contains but one nucleus "vhich may be 

 oval in shape or bent almost at y-i £ht ai.trles (T'ir. 52(d) ) but 

 in the majority of cases there are undoubtealy tv;o nuclei, 

 (Pig. 52(c) ) Fig. 52(e) shov;s a cross section throui^n one of 

 these bodies. If a transverse section of tne nephriaial pro- 

 cesses is t^en(Fijj . 52( i) ), it is seen that each has a definit; 

 wall and that inside there is a definite dot which I take lo be 

 a cross sectic"n tn'*,''''^L. '^x. /lc£iellum. This fxa^j,- j.j.';ia hcta i'^o 

 „'"it:Jn from th" cell bv^d" rj.t the end of tne process aaid the in- 

 dications are that the flat:,ellum extends throut^icut the len^rth 

 O'' the process into the lumen of the nephriaial tube. 



I am not prei.area to say that the cell bodies at the end 

 of ti.e excretory processes are ccmposea of t v.o cells but it is 

 a fact that two nuclei exist ana 1 have not drav.n this coi. elu- 

 sion from sections throui^i: bent nuclei which mifc^ht lead one to 

 think that there were tvx) v.hen only one existed. It v.dll be 

 seen from this description that the anatomy of the excretory 

 cells 8jid processes o :!'■ the Actino tro chae v/hich I hcive studiea 

 resembles that of similoT- structures described by Goodrich for 

 Ajiiphioxus. 



