An AmpJdpod Crustacean. 1 1 1 



sacs extending from their attachment at the anterior end of 

 the intestine, two-thirds the length of the body. How are they 

 held in place? Does the anus open dorsally or ventrally? 

 Draw. 



Excretory System. A pair of small, somewhat coiled 

 diverticula, the mesenteric tubules, are to be seen lying along 

 each side of the more posterior portion of the intestine. 

 Trace out their course and see where they open into the 

 intestine. The external openings of the antennal glands 

 may be observed, near the median ventral line, as two small 

 pores, each on the basal joint of a second antenna. 



Draw, as seen from the side. 



The Reproductive System. The testes are to be 

 observed as a pair of delicate tubes lying longitudinally, 

 immediately above the middle portion of the intestine. 

 Follow both to their external openings. Are the testes in 

 the thoracic or in the abdominal cavity? 



Draw. 



The ovaries occupy a position similar to that of the testes. 

 The openings of the oviducts may be found at the bases of 

 the fifth pair of appendages. Each is a small pore between 

 the gill and the oostegite. 



Draw. 



The Circulatory System. The heart \\\\\ be found as 

 a delicate elongated sac lying along the dorsal part of the 

 thoracic cavity. The blood enters the organ through cer- 

 tain lateral ostia and is then forced, through anterior and 

 posterior aortcz, into the various lacunae of the body. The 

 blood finally reaches the gills, situated, as has been observed, 

 on the thoracic segments. It is from them returned to the 

 heart. 



