208 



BULLETIN OF THE MUSEUM OF COMPARATIVE ZOOLOGY. 



ABBREVIATIONS. 



The right side of the animal is indicated by the tetters dx., the left side by s. These 

 letters are usually affixed to one or mure of the abbreviations used to designate organs. 

 The skeleton figures immediately under the number of a fgiire on the plate indicate the 

 number of the section in the series to which the figure belongs. Consult also " Index to 

 Stages " (p. 207). 



Upper lip. 

 Lens. 



Lateral lobe of brain. 

 Ciliated ridge. 

 Mantle. 

 Nerve. 



Nephridial organ (primitive kid- 

 Eye, [ney.) 

 Otocyst. 

 OEsophagus. 

 Pedal ganglion. 

 Foot. 



Pleural ganglion. 

 Pleuropedal connective. 

 Pleuro-visceral connective. 

 Cell proliferation. 

 Radula sac. 



Retractor muscle of tentacle. 

 Left. 



Pleural groove. 

 Ocular tentacle. 

 Labial tentacle. 

 Visceral ganglion. 

 Viscero-pleural connective. 



