132 University of California Publications in Zoology [Vol. ls 



As shown in table 4, Euphausia was taken in greater numbers at 

 the surface in June and July, and a consideration of its distribution 

 as regards temperature should deal with those hauLs. Table 7, how- 

 ever, which follows, includes all the so-called summer hauls. There 

 are but five successful hauls, and it is very questionable whether the 

 results of the tabulation can be regarded as having much weight. The 

 table is presented for what it is worth. 



TABLE 7 



Distribution of Euphausia During the Summer, at the Surface, With Regard to 

 Different Temperatures, None Below 15? 1 





Temperatures 



No. 

 Total 



of hauls: 



Success. 



No. 

 Total 



of hours : 

 Success. 



No. of 

 Total 



animals: 

 Per hour 



Frequency : 

 Haul Time 



1. 



15?1-16° 



1 







0.3 























2. 



16?1-17° 



32 



1 



23.5 



0.6 



109 



4.6 



o 



3 



3. 



lv?l-18° 



28 



2 



23.2 



1.5 



16 



0.7 



( 



6 



4. 



18?1-19° 



25 







17.1 























5. 



19?l-20° 



36 







28.3 























6. 



20 ?1 and more 



35 



2 



23.1 



0.8 



60 



2.6 



5.5 



3 



It is shown in the table that the likelihood of the capture of many 

 specimens below 16 ?1 is exceedingly slight during the summer, because 

 the number of hauls is so small, while, as far as the number of hauls 

 is concerned, the chances are about equal above 16?1. As the table 

 stands, the interpretation to be given is that Euphausia does not 

 exhibit marked behavior toward temperature during the summer. It 

 has been shown in table 5 that Euphausia is obtained in. greater 

 numbers with the Kofoid net in December, when the temperature must 

 be below 17° (see table 6) since sub-surface temperatures are not 

 higher than the surface temperatures. This schizopod is more abimd- 

 ant in the Nansen hauls in March (table 5, part II) and sub-surface 

 temperatures should be less than 16° during that month (see table 6). 

 If it may be assumed that the results of surface collecting are not to 

 be entirely disregarded on account of the few successful hauls, temper- 

 ature is not a factor of much importance in the determination of the 

 surface distribution of Euphausia. 



The case with Nyctiphanes appears to be different, on accoimt of 

 a larger number of successful hauls as well as because there is a larger 

 number of animals. Table 8 considers the w^inter hauls and the occur- 

 rence of Nyctiphanes in them according to temperature. 



