n6 Invertebrate Zoology. 



body, through certain irregular channels, to the pericardial 

 sac, from which it passes into the aorta through a series 

 (eight pairs) of ostia. 



Make drawings illustrating the course of the heart and 

 principal blood-vessels. 



The Digestive System. Remove the heart and expose 

 the more ventrally lying alimentary tract. The mouth will 

 be found to lead into an anteriorly and upwardly directed 

 oesophagus which opens into a strong-walled anterior stomach 

 or crop. Cut the crop open and note the character of its 

 lining. The crop opens posteriorly into a thin-walled stom- 

 achy which extends, without any remarkable change, to the 

 short proctodceum or rectum, the latter opening to the ex- 

 terior through the anus. 



Carefully open the stomach and note the entrance of the 

 bile-ducts. These bile-ducts lead from the voluminous liver, 

 which nearly fills the cavity of the cephalothorax. 



Make a drawing of the digestive system. 



The Reproductive System. The sexes are separate. 

 The ovaries or testes form a network of tubes which ramify 

 over and through the substance of the liver. Their ducts 

 may be traced to the external openings already noted. 



The Excretory System. The coxal glands lie along 

 both sides of the stomach, each consisting of a longitudinal 

 portion, from which project laterally four finger-shaped 

 lobes. In life they are " brick-red ' in color. The func- 

 tion of these organs is not definitely known. 



Draw. 



The Nervous System. Remove the alimentary tract 

 from the beginning of the crop to the anus, and expose, 



