4,4, A. O. OUDEMANS. 
Left. Right. 
125 ; 5 ; : 125? 
134 ? : : ; ; 135 
145? . : : ‘ 146 
157 : : ‘ : 166 
188 : : : 3 184 
199 ; ; . 4 200 
213 ; ; : ’ 213 
222 ‘ : 4 : 223 
Nothing . : : : 231 
285 : : : . Nothing. 
290 : : : : 294 
309 ; ‘ : ; 310 
The excretory ducts, as in all the foregoing species, are 
projected above the nerve stems, and, as in Valencinia, 
nearly touch them; but, as to their further course through 
the outer longitudinal muscular coat, I saw some running 
straight to the skin, some downwards, and others even very 
obliquely rising upwards. 
The excretory ducts for the most part were well developed 
(probably I had a nearly full grown individual) ; some of them 
were extraordinarily enlarged, but all were contracted by the 
basal membrane and in the skin, so that the external opening 
was only a few mikromillimetres. The cells in the walls are 
smaller than those of Valencinia, and placed otherwise, not 
shaped like palisades but like a pavement, and not pressed 
against one another but apart. Their nuclei seen from the 
side were flat and rectilineal, and from above ellipsoidal ; but 
all these appearances may be the results of a stretching of the 
outer muscular layer. The histological structure of the canals 
of the system is the typical one (cf. Von Kennel). I have not 
seen cilia in them, nor direct communication with the lacunar 
blood-spaces. 
6. Lineus sanguineus (Rathke), MclInt., figs. 17, 18, 54. 
In the main the same vascular system as Polia curta, 
except in the head, of which the lacune are arranged other- 
wise. 
