158 



TEXTBOOK OF ZOOLOGY 



line. These paddles are tlie locomotor organs. When seen from 

 the side, the paddles resemble a comb. The mouth is in the oral 

 end of the body and leads into the stomachlike stomodeum which is 

 connected with a series of canals running through the body. This 

 stomodeum is lined with ectoderm and leads to an infundibulum or 

 gastTOvascular cavity proper which joins the stomodeum at right 



51 



iflgitial or StomacS Plane 

 Left CAitrovfticular Cansl 





Tentaeulftt 'NviVrC^j 



Sheath ""~-;,.r 



Tentacle 



■ -S 



A '-i 



Bilobed Stomodaeum 



Right CastrovBicular Canal 

 lUdial CanaU 



^^ Intcrradial Cant, 



i^j.^ ; , '• ■ »j ^r) .i T . ' i — Tranaverse or 

 'Yvi^^—--''' • Infundibular Plane 



/.'/ ■ ;■.-• "^ Aboral 5cn«e Orgon 



■.■..■•■•;■',:;'•■•'""" — ~ - Plate row with 



Infundibular Canal underneath 



Diagram looking down on aboral pole 



Pleurobrachia bachei 



Aboral End 



InfunJibuTum 



^ ^ Slomodaeuni 



Inlerradial 

 Canal 



Plate Row with ' 

 branch of infundibular 

 canal ayilem undetnealh 



'C^ Radial 

 \ Canal 



o.. Bilobfff 

 Stomo<faeuin 



■ Mouth 



Perspective! Drawing a}ong infundibulai plane 



Oral End 

 Pcispcctivt Drawing along sagittal or 3tomodaeum pUne 



Yig, 76. — Pacific comb jelly, showing external features and structure. (Courtesy 



of Pacific Biological Laboratories.) 



angles. This cavity is lined with endoderm; undigested food is 

 egested through the mouth. The six canals mentioned above are 

 called excretory canals. There are two blind canals extending from 

 the infundibulum beside and parallel to the stomodeum; these are 

 called paragastric canals. The tentacular canals lead to the meridio- 

 nal canals lying beneath the ciliated plates. There are two blind 



