TABLE OF CONTENTS. 



Page 



Introduction 301 



Systematic characters of the Opistho- 



braiicliiata 301 



Tectibranchiatu 301 



Aplysoidea 301 



Aplysiidae 302 



Aplysiinae 302 



Dolabriferinae 302 



Dolabellinae 302 



Dolabella Lamarck 303 



D. scapula (Martyn) 304 



D. ecaudata (Rang) 304 



D. teremidi (Rang) 305 



D. gigas (Rang) 305 



D. hasseltii (Ferussac) ..... 305 



D. hemprichii Ehrenberg .... 305 



D. guayaquilensis Petit 305 



D. elongata Sowerby 306 



D. californica Stearns 306 



D. neira Sowerby 306 



Dolabella agassizi, sp. nov. .... 306 



External characters 307 



General form and color . . . 307 



Dimensions 307 



Foot 308 



Epipodia 308 



Pallial complex 308 



Shell 311 



Internal anatomy 312 



Alimentary tract 312 



Pharyngeal bulb 312 



Mandibles 313 



Radula 316 



Palatal folds 318 



Page 



Palatal spines 319 



Salivary glands 323 



Oesophagus 323 



Ingluvies and triturating stom- 

 ach 323 



Liver and intestine 325 



Reproductive system 325 



Ovotestis 326 



Small hermaphroditic duct . . 326 



Adnexed genital mass .... 326 



Spermatocyst 327 



Albumen and nidamental glands 327 



Large hermaphroditic duct . . 327 



Spermatotheca 328 



External spermatic groove and 



penis 328 



Nervous system 329 



Central nervous system . . . 329 



Cerebral ganglia , 330 



Cerebral nerves 330 



Pedal ganglia 333 



Pedal nerves 334 



Parapedal commissure .... 337 



Pleural ganglia 33S 



Pleural nerves ...... 33S 



Buccal ganglia 339 



Buccal nerves 340 



Parieto-visceral ganglia , . . 341 



Visceral nerves 342 



Parietal nerves 344 



Respiratory, circulatory, and excre- 

 tory systems 344 



Literature 346 



Explanation of plates 



