122 CRUISE OF THE BARRERA 



Medusae and Actinians which were successfully 

 expanded in the magnesia bath. Among the 

 trophies of the day were some exceedingly beau- 

 tiful Solids of pure white, with edges painted in 

 brilliant yellow. These nudibranch mollusks are 

 the veritable butterflies of the sea. Their colors 

 are startlingly vivid and their schemes of decora- 

 tion often fantastic and wonderful. This exten- 

 sive group of beautiful creatures inhabiting all 

 seas, of infinite variety and of superlative interest, 

 offer a most inviting field for investigation. Many 

 genera and species have been described and illus- 

 trated in color plates, but every day's collecting in 

 favorable stations brings to hand specimens that 

 defy identification and are more beautiful than 

 any yet pictured in books. It takes a practiced 

 eye to detect them in the mess of rubbish dumped 

 from the dredge, for when disturbed these delicate 

 creatures contract into shapeless little masses that 

 appear to be of no importance and are allowed to 

 fall into the discard. When placed, however, in a 

 jar of clear sea water and permitted to rest for a 

 time undisturbed, these little lumps of nothingness 

 gradually unfold into exquisite beings. For pur- 

 poses of preservation, the beauty of our nudibranch 



