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Figure 66. — Onuphidae, Diopatra cuprea {d-e, after Moore, MS.): a, dorsal view anterior 

 end; b, 1 of spiralled branchia; c, dorsal view posterior end; d, mandibles, ventral 

 view; e, dorsal view maxillae, the anterior accessory pieces of maxillae V displaced. 



Branchiae (fig. 6Q,a,b) begin on setigers 4 or 5, arising on the inner 

 side of the bases of the dorsal cirri, with a short, cyhndrical, more or 

 less ringed base, with branchial filaments emerging in spiral fashion 

 from a central stem. Stem and filaments each with 2 blood vessels. 

 Branchiae largest anteriorly, getting smaller with fewer branches more 

 posteriorly, the more posterior branchial segments with 2 and then a 

 single short branch. Usually about 30 pairs of branchiae (up to 43, 

 fewer on smaller specimens). Anterior branchial segments with 

 straight and curved setae with fine tips. Middle and posterior 

 branchial segments with central conical lobe surrounded by ring of 

 setae, with setae of 3 kinds: (1) Upper bundle of short comb setae 



569-457— G3- 



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