BY THOS. L. BANCROFT. 



dl 



London Zoo are healthy enough, but it may be that too much 

 light or noise irritates them ; at any rate, fish in their natural 

 home do not behave so. 



During flood time they rise more frequentlj'^ ; as a 

 general statement it might be fairly accurate to say Ceratodus 

 breathes air several times in a day of twenty-four hours. 



Text-figure 9. — Outlines of Ceratcdus. 

 a. At birth (13mm.); b. two months old (23mm.); c. three months 

 {30 mm.) ; d. four months (36mm.) ; c. five months (53mm.) ; /. six months 

 {iJ2mm.) ; g. seven months (75mm. — weight, 30 grains); h. two years 

 (I23mm. — weight, 144 grains). 



