HABITS OF IANTHINA. 519 



carapace. These rare and interesting little animals have 

 been ascertained by Dr. Baird, who has studied profoundly 

 this little known and difficult branch of Zoology, to be 

 specifically distinct, and he has done me the honour to de- 

 dicate them to me under the name of Cypridina Adamsii ; 

 they are the third and largest species known. 



The eyes Qi lanthina are very minute, and terminal at the 

 end of a peduncle, the animal, in this respect, and in having 

 a long extensile proboscis and divided foot, resembles a 

 Strom bus. In the act of swimming, the dilated natatory 

 appendages of the mantle are kept fully expanded, but I 

 never observed them used in the same manner as the alar 

 expansions of theffyaltea, although, doubtless, in their pro- 

 gression through the water, their use is very great. The 

 vesicular float adhering to the posterior flattened division 

 of the foot, which is considered by some to be an extra- 

 ordinary form of operculum, has the egg-sacs attached 

 by short peduncles to the surface, and the female lanthina 

 appears to have the power of detaching that portion of 

 the float to which the nidamental sacs are fixed, which 

 then remains suspended on the surface of the Avater, 

 where, exposed to the influence of heat and light, the ova 

 undergo their ultimate development. Although we found 

 these beautiful Mollusks cast up by thousands on the 

 shores of the Me'ia-co-shimahs, I never observed them make 

 the slightest effort to crawl, but have frequently noticed 

 them adhering together in masses, attached by the ante- 

 rior part of the foot, which acts as a sucker. In company 

 with the thousands of lanthina swimming on the surface 

 of the South Atlantic, were innumerable little fish of the 

 genera Gonostoma, fcktbyococcus, and Scopclus, some of 



