THE ANNALS 



MAGAZINE OF NATURAL HISTORY. 



[SEVENTH SERIES.] 

 No. 26. FEBRUARY 1900. 



XVIII. — On the Nephridium of Nephthys caeca, Fahr. By 

 Francis Hugh Stewaut, M.A., Gatty Marine Laboratory, 

 St. Andrews. 



[Plates II. & in.] 



During the summer of 1899, while working at tiie Gatty 

 IVIarine Laboratory, St. Andrews, it was suggested to me by 

 Professor M'Intosh that, in view of the wonderful supply of 

 living material obtainable in St. Andrews Bay, it might be 

 profitable to continue the work of Mr. Edwin Goodrich on 

 the nephridium of Nephthys (Q. J. M. S. no. 157). In so 

 doing I have been able to contirm Mr. Goodrich's results 

 in all points except one — the position of the organ relative 

 to the blood-vessels. This, as described and figured by him, 

 is briefly as follows : — The ciliated organ lies in the angle 

 between the dorso-ventral vessel and the branch x (PI. II. 

 fig. 1) ; the nephridial tube passes down the dorso-ventral and 

 along the branch y, the solenocyte-bearing tuft resting in 

 the angle between the dorso-lateral and the branch x. 



After a most careful examination of the subject, I have 

 come to a different conclusion. The ciliated organ rests, not 

 between the dorso-ventral and x (PI. It. fig. 1), but at tJie 

 junction of the ventro-lateral, the dorso-ventral, and y; the 

 solenocyte-bearing tuft lies in the angle between the ventro- 

 lateral and the dorso-ventral, not between the dorso-lateral 



Ann. c£- Mag. N. Hist. Ser. 7. Vol. r. U 



