of Littorina Angulifera. 341 
the cesophagus ; they empty, by two ducts, into the cavity of 
the buccal mass. 
The liver (27), conjoined with the testicle (28), in the male, 
or the ovary of the female, forms the superior portion of the 
turbinated mass of the animal. From the testicle, in the male, 
_ proceeds the vas deferens (29), on the outside of the rectum, 
to join the penis. In the female, from the ovary, proceeds the 
oviduct, having nearly the same appearance and the course of 
the vas deferens of the male ; it terminates by a projecting 
extremity, just on the outside of the projecting extremity of 
the rectum, The nervous centres consist of the supraceso- 
phageal ganglia (30), the stomatogastric ganglia, a small gang- 
lion on each side of the cesophagus, and the subcesophageal 
ganglia, all connected by the appropriate commissures, and 
giving off nerves. "To the subcesophageal mass, composed of 
‘Wo apparent ganglia, is attached the auditory apparatus, 
Which consists of two vesicles, each containing two large oto- 
conites. The otoconites are translucent, and composed of 
Concentric lamellae ; this is evident from their appearance 
under the microscope, after having been submitted to pressure, 
as represented in fig. 3. 
REFERENCE TO THE FIGURES. 
Il. The operculum ; 12. The branchia; 13. The collar; 14. Branchial 
Vas 15. Heart; 16. Aortie branch to the head ; 17. The renal organ ; 
= Its duct; 18. The visceral sac, laid open; 19. The buccal mass; 
93 $ coiled palatal lamina; 21. Stomach; 22. Duodenal pouch ; 
` Small intestine; 24. Rectum; 25. Extremity of the rectum; 26. 
def, glands ; 27, 28. The liver and testicle conjoined ; 29. The vas 
mil i 29*. Cut extremity of the vas irm (its co: ! ection to the 
estroyed) ; 30. Supracsophageal ganglia. i 
Fig. 9 "acie a eben of Fg uncinated palatal surface, highly 
Fig. 3 represents the organ of hearing, highly magnified. 
