244 



THE AMERICAN NATURALIST 



[Vol. XLI 



rather than coincident in their distribution. There is thus little 

 conclusive evidence of coincident distribution in the few species 

 of Krohnia. 



Genus Spadella 



The case of the two species of Spadella, S. cephaloptera and 

 S. draco the area of distribution of the latter, which is a wide one, 

 includes that of the former which is a neritic species from the 

 northwestern coasts of Europe and the Mediterranean. They are 

 both surface forms and their distribution is of the coincident type. 



Genus Sagiti'a 



The genus Sagitta as revised by Fowler (:06) includes twenty- 

 one species. Their general horizontal and vertical distribution 

 is shown in the accompanying table taken from Fowler's (:06) 















































J 













I 



1 



1 



I 



1 



1 



1 

 1 



1 



1 

 1 



1 

 1 



I 



1 



1 



i 



i 



1 







i 



t 



i 







t 









t 



t 









t 













i 

















\ 

























i 



























































: 















(Siboga) report. S. bipunctata is omitted by him from the Indo- 

 Austral region in his text because of the uncertainty of its identifica- 

 tion since it is quite similar to the young of several other species 

 in the list. Of the twenty-one species, eleven, including S. bipunc^ 



