280 NEW YORK STATE MUSEUM 



that of the penis. For about one half of its length it is thickened, 

 annulated and glandular, becoming cylindric and filiform, enter- 

 ing the penis on the side, just anterior to the extremity. 



The uterine canal is conspicuous, but does not present so dis- 

 tinctly a sacculated appearance as in P. a 1 b o 1 a b r i s. 



The albumen gland is large, flattened, rounded at each extrem- 

 ity, broadest at the anterior, gradually diminishing to the pos- 

 terior. 



The hermaphroditic duct is short, tlexuous, but not convoluted, 

 as in P. a 1 b 1 a b r i s. 



The ovotestis consists of an oval, flattened mass^ formed by an 

 aggregation of ceca. It is nearly four times as long as wide; situ- 

 ated on the dorsal part of the posterior end of the digestive gland. 

 It differs greatly from the ovotestis of Polygyra. 



Circulatory system 

 Plates 18, 19 



Heart. The heart is situated at the lower left side of the 

 pulmonary chamber. It consists of a single auricle and ventricle, 

 each pyriform, placed base to base, the bases being truncated. 

 The auricle is anterior to the ventricle and about one half its size. 



Arteries. The aorta (pi. 18, fig. 1) proceeds from the apex of the 

 ventricle, and almost immediately divides into two principal 

 branches, the anterior and posterior of about equal diameter. 

 The aorta divides before leaving the pulmonary chamber, giving 

 the appearance of two aortae proceeding from- the heart. 



The anterior artery proceeds for a short distance laterally^ then 

 anteriorly. It supplies the stomach, salivary glands, penis, recep- 

 taculum seminis, buccal body and nerve ganglia. At the gangli- 

 onic mass it turns abruptly backward, and proceeds along the mid- 

 dle of the ventral part of the animal, immediately above the pedal 

 sinus; continuing for about one half the length of the animal, then 

 bifurcating and entering the foot. 



Where the artery bends forward a large branch is given off to 

 the crop. This branch almost immediately subdivides, the princi- 

 pal branch proceeding anteriorly on the dorsal part of the crop. 



