40G Mr. G. C. Ilol)Son on the 



3. The urinary cavity (" Urlnkanimer ") resembles tliat 

 foniid in the Paludestrinidro. It ramifies among the 

 other organs, and is lined by a characteristic epithelium 

 composed of vacuolated cells with basal nuclei. 



Fig. 3. 



H. nosojyhora (-rV horn. iinm. x \ oc). 

 Part of trabecular area of kidney. 6 = blood- 



JY . Circulatory Syst 



em. 



The ]iericardium is situated in the usual position. No 

 tiace of a reno-pericardial aperture was found, though it is 

 not certain that it is absent. 



Tl\\e auricle and ventricle are*normal. The latter is very 

 muscular and its cavity is traversed by numerous muscle- 

 iibres. Some indication is seen of an aiiriculo- ventricular 

 valve. 



The distribution of anterior and posterior aortae is normal, 

 the anterior running forwards over the roof of the ])ericardium 

 for some distance, tlien accompanjiiig the oesophagus to open 

 into the ce})haio-pedal sinus. The posterior aorta runs 

 backwards between the stomach and intestine. It would 

 jippear that the portal vein enters the pulmonary vein before 

 the latter reaches the auricle; but it is impossible to be abso- 

 lutely certain of this point. 



The cephalic and pedal portions of the anterior {cephalo- 

 2)edal) sinus are incompletely separated by a horizontal 



