128 



University of California Publications in Zoology [Vol. 13 



TABLE ^—{Continued) 



Haul number 

 2933 



Euphausia 

 pacifica 



N 



vc 

 s 



iphanes 

 inplex 



7 



Thysanoessa 

 grcgaria 



Nematoscelis 

 difficilis 



2937 



5 















2938 



5 















2963 









2 











2968 















3018 

















3020 









1 











3025 









1 









3056 

















3060 













1 





3093 













.... 



3103 















3137 



















3195 













.... 



3199 













.... 





3202 

















3219 















.... 



3272 













1 



It is rather surprising how little is known about the behavior of 

 the schizopods, although the group is one of the best known among 

 the Crustacea from the systematic side. There is a short paper by 

 Fowler (1905) concerning the movements of these animals, and Holt 

 and Tattersall (1905) briefly discuss behavior. Both these papers 

 deal only with field data, and so far as I know there are no other 

 references on the subject. 



In considering the distribution of the Schizopoda it is necessary 

 to keep in mind that their eyes are highly developed and apparently 

 very serviceable organs. Consequently the possibility deserves to be 

 considered that large catches, at night, for example, are obtained 

 because the animals cannot see the nets, while during the day they 

 could avoid capture. The organisms are powerful swimmers and 

 probably active enough to get out of the way of the slow-moving 

 surface nets at least. It may be said here that Fowler inclines to the 

 view that facts appear which cannot be accounted for by supposing 

 that the animals see the nets, and I concur in this for reasons that 

 will appear later. 



The question of seasonal occurrence is one that always has to be 

 considered, and in table 4, which follows, there are set down the sur- 

 face hauls by months, together with the number of hauls (total and 

 successful) and the number of animals of each species in each month. 

 There appears also the haul frequency for every month. 



