BY T. HARVEY JOHNSTON AND T. L. BANCROFT. 59 



This specimen was just seven months old and had been 

 reared, along with a few others, from the egg stage by Dr. 

 Bancroft. It was killed to serve as a record of the work, 

 the remaining fish being still alive. Pelvic fins were dis- 

 tinctly visible to the naked ej^e Avhen the fish were two 

 and a-quarter inches long and about six and a-half months 

 old. 



The third exhibit was a very J'^oung Ceratodus, six 

 weeks old {i.e., after hatching), and measuring 17 mm. in 

 length, the tail being only a httle over one third of the 

 total length of the animal. It possessed very simple 

 pectoral fins, but there was no trace of the pel vies. The 

 specimen showed a distinct advance in development 

 on the four-weeks-old larva figured by Semon. 



