Table 2. --Pteropods of the North Pacific and the faunal zones in which they 

 occurred: data from Charles H. Gilbert cruise 23 and 

 Hugh M. Smith cruises 27 and 30 



* = present, ** = common. *** = abundant 



(Note: Cymbulidae and naked pteropods not identified) 



became evident that most of them were 

 generally distributed, the species connposition 

 changing only slightly among the several zones. 



General Abundance and Distribution 



A prelinninary study of the plankton samples 

 from Hugh M. Smith cruise 30 has shown that 



regardless of time of day of hauling, oblique 

 hauls between the surface and 40 m. yielded 

 larger numbers of chaetognaths and pteropods 

 per m.-^ of water strained than deeper hauls 

 between the surface and 140 m, (table 3). A 

 similar relation to depth was found in the 

 tropical Pacific (Hida and King 1955) and in the 

 North Pacific (Brodskii 1955). 



Table 3. --Variation in number (no. /lOOOm.-^) of chaetognaths and pteropods with depth and time 

 of hauling for the three faunal zones, as found on Hugh M. Smith cruise 30 



