68. Sargassum sea slugs, Scijllaea pelagica, live attached to floating sargassum sea- 

 weed. One of the sea slugs, freed from the seaweed, shows two pairs of leafiike ex- 

 tensions from the back that serve as gills. Two still cling to the seaweed, which is 

 covered with delicate little branching colonies of a hydroid. (Marineland, Florida) 



69. The sea slug shown in Plates 62 and 

 64 is here shown laving a spiral ribbon 

 of eggs against the glass of an aquarium. 

 (California. Woods- Williams) 



