826 EDWIN S. GOODRICH. 



right reno-pericardial canal separated off from the pericardium, 

 and lying close to the wall of the subrectal portion of the 

 right kidney. From the pericardium a second diverticulum is 

 seen coming off at a higher level than the first, — it is the begin- 

 ning of the left reno-pericardial canal. If we compare this 

 figure (fig. 2) with fig. 25 b, pi. xxxvii of Erlanger's memoir, 

 we can hardly doubt but that he actually figured the origin of 

 the left canal without understanding its true nature ; for no- 

 where else does the right wall of the pericardium become 

 folded or pushed out at this level as v. Erlanger represented. 

 Neither of the canals opens straight into the renal coelom, — on 

 the contrary, they bend forwards and extend along the walls 

 of the kidneys for some considerable distance. The right 

 reno-pericardial canal is especially long. If we follow the left 

 canal to about one third of the way between its place of origin 

 and the external aperture of the left kidney, we find that it 

 opens into this kidney (fig. 3) through its left wall. Tracing 

 out the right or lower canal farther forwards, we find it opening 

 into the subrectal region of the right kidney, about two thirds 

 of the way from its origin to the right renal pore (fig. 4). In 

 both cases the reno-pericardial opening is situated at the end 

 of a papilla projecting into the renal coelom, and forming a 

 ciliated funnel-like spout. 



The excretory epithelium of the kidneys (fig. 9) is formed of 

 a layer of very tall cells, the free ends of which are much 

 swollen, and often broken off. They sometimes bear cilia. A 

 round nucleus is situated towards the base, and outside it are 

 numerous excretory granules ; the swollen distal end appears 

 almost empty — an effect due, no doubt, to the reagents. At the 

 rim of the funnel (figs. 6 and 7, and the reconstruction in 

 fig. 5) this epithelium changes suddenly into ordinary high 

 columnar epithelium, provided with numerous long and powerful 

 cilia directed towards the renal cavity. Near the base of the 

 funnel the ciliated epithelium passes into the flat coelomic 

 epithelium lining the canal (fig. 8). The pericardial epi- 

 thelium itself is identical and perfectly continuous with that 

 of the canal. 



