304 NEW YORK STATE MUSEUM 



Fig. 



6 Transverse section of a specimen: 1 mantle; 2 envelop of 

 the shell; 3 shell; Jt, 5 pulmonary veins; 6 pulmonary 

 cavity; 7 mucous part of the integument; 8 muscular 

 substratum of integument; 9 muscular peritoneum; 10 

 muscular and mucous basal integument; 11 visceral 

 cavity. 



PLATE 17 



Generative organs 

 Pia. 



1 1 genital opening; 2 penis; 3 vas deferens; 4 spermatic 



duct; 5 retractor muscle of the penis; 6 receptaculum 

 seminis; 7 free oviduct; 8 uterine canal; 9 albumen 

 gland; 10 hermaphroditic duct; 11 ovotestes. 



2 Penis retracted, x 3. 



3 Penis exserted, x 3. 



4 Ovotestes, x 4. 



5 Ceca of the ovotestes, enlarged. 



6 A still farther enlargement of the ceca. 



7 A transverse section of the penis and vas deferens, x 6. 



PLATE 18 



Circulatory system, x 3 

 Fig. 



1 1 aorta as it leaves the ventricle; 2 anterior aorta; 

 3 arteries to the crop; 4 arteries to the uterine canal; 

 3'^ arteries to the stomach, intestine and digestive gland; 

 5 artery to the lower salivary gland; 6 artery to 

 upper salivary gland; 7 posterior aorta; 8 arteries to the 

 intestine; 9 arteries to the digestive gland; 10 artery to 

 ovotestes; 11 artery to penis; 12 artery to vagina and 

 receptaculum seminis; 13 artery to buccal body; 14 

 artery to commissural cords; 15 arteries to tentacles; 

 16 artery to basal part of the body. 



