82 Transactiuiis. — Zoology. 



One of tlie specimens was a pregnant female, and con- 

 tained an innnensc number of young. Both the adult and the 

 embryos agree in general characters with the figures oiFilariu 

 medincnsia of Bastian and Leuckart, and seem to be a species 

 of Filar ia. 



DESCRIPTION OF PLATES XII.-XV. 

 Lotella hacchus. 

 Plate XII. 

 Enteric canal, distended with alcohol. 

 Gall-bladder, showing the hepatic ducts. 

 Tlie liver ( x A), showing lobes and main lobules. 

 Pseudobranch after the removal of the mucous membrane of the 

 mouth. 



Platk XIII. 



Auditory organ. (x2.) 



Auditory organ in situ, showing its relation to the air-bladder. 



The large otolith. 



TJie small otolith, from above. 



The small otolith, from below. 



Frozen Sections. 

 Fig. 11. Through the body, just posterior to the supra-occipital spine. A 



posterior view. 

 Fig. 12. Through the anterior part of the stomach. An anterior view. 

 Fig. i;?. Posterior view of the same section. The drawing is reversed so 



as to make it correspond v.'ithfig. 12 in position. 

 Fig. 1-1. Through the anus. An anterior view. 

 Fig. 1.5. Through the posterior end of duodenum. An anterior view. 



Plate XIV. 

 Frozen Section. 

 Fig. 10. A longitudinal vertical section, extending from the anterior end 

 of the body to a short distance behind the posterior end of the 

 abdominoi cavity. This section, besides showing the main 

 viscera, the heart, the air-bladder, the brain and spinal cord, 

 in their relations, shows also the articulation of the inter- 

 spinous bones and dermal-lin rays. The stomach is relaxed, 

 and consequently the mucous membrane is thrown into folds. 



Plate XV. 



Fig. IG. A longitudinal vertical section of the brain, taken about the 

 middle line. This is intended mainly to show the continuity 

 of the cavities of the brain, and especially the relation of the 

 cavity of the prosencephalon. It is partly after Weidersheim's 

 tlgure from Rabl Riickard (the pineal body taken entirely 

 from this figure). 



Fig. 17. A transverse section through the anterior portion of the optic 

 lobes of the brain. 



Fig. 18. A transverse section through the epencephalon and meten- 

 cephalon near the posterior end. 



Fig. I'J. A transverse section further forward than fig. 18. 



Fig. 20. A transverse section through the anterior part of the brain, 

 Khowiiig pnlliu)n, commissure, Ac. 



