1911] Michael: Chaetognatlia of the San Diego Region. 141 



EFFECT OF LOCALITY ON THE DISTRIBUTION OF 

 S. BIPUNCTATA 



As in the case of seasonal collecting, our closing nets were 

 not employed at all stations. Consequently a consideration of the 

 effect of locality, or distance from the coast, on distribution 

 limits us to surface collections. While definite seasonal effects 

 on distribution could not be discovered, it is very probable that 

 some such effect exists. It seems, therefore, advisable to restrict 

 this consideration to June and July data. These data are sum- 

 marized in the accompanying table. 



From this table we find that conditions of salinity, tempera- 

 ture, and time of day under which the hauls were made varied 

 from station to station. With such an amount of variation no 

 significant effect of locality on distribution can be detected. 

 From the table we see that those stations where the abundance 

 of specimens is greatest are those where the most twilight hauls 

 were made. This indicates that very little, if any, difference in 

 distribution exists with respect to distance from the coast. At 

 any rate, until more definite collecting regarding this problem 

 is accomplished, no definite conclusions are possible. 



