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PROCEEDENGS OF THE NATIONAL MUSEUM 



a 



Figure ^.—Aquaplana pacifica: a, dorsal view; b, eyes enlarged; c, copulatory apparatuses 

 as seen looking down on whole animal. (Explanation on page 597.) 



These course separately from the spermiducal bulbs through the thick 

 muscular wall of the cirrus sac. The cirrus sac is of elongated conical 

 form, gradually narrowing to the male gonopore. Posteriorly its 

 wall continues as a cirrus papilla, armed with a few teeth, that projects 

 posteriorly beyond the male gonopore and is basally enclosed in a 

 short male antrum. There is no other armature of the male apparatus 

 except the teeth or thorns on the cirrus papilla. 



