certain points in the anatomy of chiton. 101 

 Fig. 1. 



A diacraminatic representation of the kidney and generative ducts of 

 Chiton discrepans, viewed from the ventral surface. The paUial groove is 

 represented as enclosed by the lines jo.y. ; and in it are seen the 16 gills 

 {br.), the generative {g.o.) and renal {r.o.) orifices; and the anus {a.). The 

 branched nature of the kidney is shown in the anterior part of the figure on 

 the right side ; posteriorly these secreting tubules are omitted. On the left 

 side of the figure the kidney duct alone is indicated. 



a., anus; Ar., branchiae ; D, dilated part of kidney duct opening to ex- 

 terior ; g. points to the junction of the generative duct with the generative 

 gland; the generative gland is supposed to be torn away; g.d., generative 

 duct ; h.k., posterior part of kidney duct ; g.o., generative orifice ; k.t., 

 secreting tubules of kidney ; k.d., duct of kidney running forward, bending 

 round at T and running back, receiving glands as far back as O. From O 

 it runs to the pericardial opening p o., receiving no glands ; p.g., pallial 

 groove; 13, 14, 15, 16, last four brauchiee; the vtulricle and auricular 

 openings are indicated by dotted lines. 



