THE NAUTILUS. 



25 



Size of Young taken from above Sphaerium by gross 

 Dissection. 





V'l'Pflllf'ilfH 



~Ppy cfiii fit 



K 

 . c 





04 



l t 



16 



6. 



1 5 



6 



9 



2. 



37 



14. 



9 T 



q 



Q 

 o . 



3. 



26 



10. 



3.5 



3 



1. 



4. 



28 



10. 



5. 



37 



14. 



6. 



41 



15. 



7. 



55 



20. 



8. 



8 



3. 



267 young from 400 adults taken haphazard. 



The size of the young was found to be independent of the 

 size of the parent. An eight-millimeter young is as likely to 

 be in a fourteen-millimeter parent as in one of eighteen milli- 

 meters length. The majority of the above contained two young, 

 one in each inner gill. A few contained four. 



Similar data were taken from Calyculina which were killed 

 in June 1913. 



Length of Parent 



Total 

 Examined 



Length of 

 young 



N limber of 

 young 



7 



1 



1.5 



7 



6 



1 



1. 



4 



8 



1 



1.5 



9 



7 



1 



1.5 



16 



7 



1 



1.5 



10 



8 



1 



2. 



5 



7 



1 



5. 



3 



The great variation in the number of young is probably due 

 to the fact that some had already emerged from the parent 

 pouch. I have no records which include totals of young of all 

 stages. In one specimen I was able to count twenty-four. 



