Explanation of Plates. 483 



EXPLANATION OF PLATES. 



PLATE VII. 



Fig. 1. General view of the dredge. See pp. 424-428. 

 Fig. 2. Upper cylinders of bucket and collecting tube. 

 Fig. 3. Bucket, stopper, and collecting tube. 



PLATE VIII. 



Fig. 1. Full sized section through front of frame of dredge 

 and part of cover, which is slipped back from frame. 



A, frame; B, support for guide; C, guide; D, cover; E, 

 flange of cover. The flange is slightly turned up at its front 

 edge, so that it will not strike the guide as the cover closes ; 

 G, eyelet for cover-cord; H, pulley; I, support for pulley; J, 

 eye on cover for attachment of cord; K, cylinder for attaching 

 dredge net; M, guide for cover. 



A section through the side of the frame would be substantially 

 the same except that the cover would be in the groove below C 

 and the flange E would not be turned up on the edge. 



Figs. II-VIII. Graphic representation of the general dis- 

 tribution of the Crustacea. The size of the circles is proportional 

 to the number from the entire depth or from each level. Each 

 circle is divided into sectors proportional to the number of each 

 kind of Crustacea. See p. 445, Table E. 



PLATE IX. 



Fig. 1. Graphic representation of the percentile distribution 

 of the Crustacea during the month of July. Each vertical line 

 in the diagram represents two per cent, of the total catch and 

 each horizontal line one meter of depth. The percentage of the 

 whole number of each species yielded by each 3 m. level is in- 

 dicated by a circle placed at the center of the level. The circles 

 or dots for each species are connected by lines. 



d, Diaptomus; c, Cyclops; h, Daphnia hyalina; p, Daphnia 



pulicaria. 

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