CEAYFISH 83 



antennary artery. The hepatic arteries are given off just poster- 

 ior to and ventral to the antennary artery. Posteriorly from 

 the heart runs the dorsal addominal artery from which the 

 sternal artery passes to the ventral surface of the body. This is 

 an open circulatory system because in the tissues of the body 

 the blood leaves the capillaries and finds its way back to the 

 heart by a series of spaces called the sinuses. 



6. Draw side view of heart and main branches of circula- 

 tory system. 



Reproductive Organs 



the female 



1. The ovary lies below the pericardial sinus, and fre- 

 quently contains conspicuous eggs. There are two anterior lohes 

 and a median posterior lohe. 



2. From the lower side of the ovary trace the large oviduct 

 downward to the external openings on the basal segment of the 

 third pair of walking legs. 



3. On the external surface upon the median line between 

 the fourth and fifth pairs of walking legs observe the annulus 

 ventralis. Following copulation sperm is stored in this until 

 the time for egg laying. 



THE MALE 



1. The testes lie immediately below the pericardial sinus. 

 They consist of two anterior lobes and one median posterior lobe. 



2. The vas deferens is a long coiled tube extending along 

 the side of the body, from the lower part of each testis to the 

 genital opening, in the basal joint of the fifth walking leg. 

 Before the breeding season has passed the vas deferens will be 

 filled with a white mass of sperm. 



3. Reexamine the appendages of the first and second ab- 

 dominal segments, as it is by their aid that a tube is formed 

 which conducts the sperm from the genital openings of the male 



