85 



PLATE XIII. 



LOBSTER AND CRAYFlSK-continucd. 



General Aeranoement of Internal Organs— 



Fiuti. 1, 2, 3. LioDY IN Sectional Plan and Elevation — 



/ Mouth. 

 j Gullet. 



I Stomach, with its cardiac or anterior end (Or. kurdia, the heart), and its 

 Alimentary System i pyloric or posterior end (Ur. puloros, ;i gatekeeper) leading into 



Intestine ending in 

 Anus. 

 I Liver made up of two symmetrical halves. 



Circulatory System { ^*^''^'''^; 



I Arteries — Sternal, superior abdominal, and inferior abdominal. 

 Kespiratory System— Branchite (Gr. gills), twenty on each side iu Lobster, eighteen in CrayPisli. 

 IvENAL System — Green glands situated at the base of antennie. 



C Supra-CBSophageal ganglia. 

 Nervous System . \ Circum-oesophageal commissures. 



J Sub-oesophageal ganglia. 



V Chain of eleven ganglia. 



( Testes with their vasa deferentia opening on the base of last thoracic 

 Eeproductive System \ appendages (fig. 2). 



J Ovaries with their oviducts opening on the base of last thoracic appcn- 



V dages but two (fig. 3). 



