LOCATION OF THE SACCULUS IN FISHES. 



29 



OPHIOCEPHALIDiE . 



pyocephalus marulius, the " Murrul " of India, an esteemed 

 freshwater table fish. This fish has an accessory breathing 

 apparatus, enabling it to use atmospheric air in respiration. It 

 often passes a considerable time under the mud of dried-up tanks. 

 The sites of the sacculi are shown by two prominent bony ex- 

 crescences of the basi-occiput that project into the cavity 

 occupied by the accessory breathing apparatus : the bone of the 

 excrescences is not transparent. The sacculi are in pockets with 



1. PSETTA LCEVIS. | 



4. Capros APER. 



7. SlLLAGO SIHAMA. 



9. MULLUS BARBATUS. 



Fig. V. 

 2. Perca fluviatilis. 3. Chirocentrus dorab. 

 5. Clupea harengus. 6. Mugil braziliensis. 

 8. Hippoglossoides limandoides. 

 10. Arapaima gigas. 11. Trigla gurnardus. 

 12. Uranoscopus scaber. 



open tops through which the sagittae could be got out. The 

 lagena, a broad prolongation of the sacculus, is embedded in 

 bone and has a pocket of its own that required careful cutting 

 open to obtain the asteriscus. The right lapillus could not be 

 found in this fish, although both were got out of another specimen. 

 The " sulcus acousticus " is well-defined (fig. VI., 1.) 



