No. 553] DISTRIBUTION OF THE CHJETOGNA Til A 45 





oms 



Species Obtained 



No. of 

 mens 



Stage of Maturity 



1,948 



2(10 



S. lyra 



2 









8. serratodentata.... 



13 



La^e ^om^ne^"^^™ 

 arge, some near y ma ure. 



1,978 



200 





1 







8 lVra tod "tata 

 K. subtilis 



1 



Large and nea rT/mature 



1,732 



220 





1 







S. serratodentata.... 



13 



LaFg e an5 ^a^mature 

 Large an near y mature. 



1,557 



250 



S. Ivra 



50 



All stapes, several nearly if not fully 





8. serratodentata.... 



24 



LaTge' but immature. 



1,729 



250 











S. serratodentata 



17 





1,550 













S. planktonis 







1,567 





S. serratodentata 



2 



Small and immature. 



ferentials would undoubtedly be established between S. 

 lyra and S. planktonis with reference to their depths of 

 maximum abundance. Again, more extensive data rela- 

 tive to all depths, by increasing the number of specimens 

 and hauls with which to deal, would enable us to split the 

 region of 250 to 350 fathoms, for instance, and thus dis- 

 tinguish strata and establish specific differences within 

 much smaller limits. However, on the basis of data al- 

 ready accumulated, all the evidence points toward the 

 probability that the fertilization of each species nor- 

 mally takes place within the limits of its depth of maxi- 

 mum abundance. 



Summary and General Significance of the Data 

 In the foregoing pages the following facts relative to 

 the question of isolation and coincidence have been re- 

 vealed : 



1. Of the most closely related "couplets" of species 

 only one occurs in the San Diego region, except in the 

 case of S. enflata and S. hexaptera, the former of which 

 can not be regarded as resident in this vicinity. 



