(31) 

 cells lyin. on the cio rsal wall of the intestine. Masteman 

 does not follov; the fate of these masses but in tt:e larva v/ith 

 three pairs of tentacles he s^-eaks of "the two mesocoels push- 

 ing aorsally their walls fc rrainj, a pair of conspicuous ruesen- 

 teries witn the wallc: of the siatacoeles" . (pa-.e o9o) 



As I hiave said before I have not found the masses o"^ cells 

 that I.'iastenrian (16) speaks of but I do not aeviy that tne condi- 

 tion v/hich he describes may not exist in t ho larva of Phoronis 

 Euskii y.'ith three pairs o "^" tentacles, 



"Ilephriciial _P i.t_^._ ( I xe d a ) 



A structure of the larva of Phoronis which has t;iven rise 

 to ccnsiaerable controversy is ti;o "nephridial pit" ("posterior, 

 anal, ectoblastic pi t" , "posterior aivert iculum" ) . It seems 

 safe to assume that such a stn;,c turo oxists in the youn^; larvae 

 0^ all species of Phoronis, It has bc^n seen by Caldwell (Zci) 

 in P. Kov.al'JvsKii , by Ikeda ^9,^ in ?. Ijimai, by Lon^chairips 

 (1?) in P. Kowalevskii, by Mastenrian (16a) in P. Euskii and 

 P. hippocrepia and by myself iu P. architecta, Althpui^ii 

 Hjule (£0) has not observed tne pit in P. Sabatieri, it seems 

 probable, tnat sucli a stri-ctrire will be fbuna tiiere on further 

 investie;ation. I can.no t believe tnat Roule's understanding 

 0-^ tj-e o^J(/in uf tn; nc:..hriciia from two cell masses of somat- 

 opleure synunetr-ically placed at the sides of the larva 



