404 United States Exploring Expedition. 



families are unknown. The ocean swarms with minute Crusta- 

 cea, and it is seldom that a hand-net is thrown in good weather 

 without bringing up some novelty. In some seas they are so 

 numerous as to color the ocean red, over many square miles of 

 surface, as was observed off the South American coast near Val- 

 paraiso. These are the red or bloody waters that have been de- 

 scribed. When thus numerous, these animals are often called 

 whale's feed, and it is believed that they are actually the food of 

 the " right whale." Each animal is not over a twelfth of an inch 

 long, yet they swarm in such numbers as to afford subsistence to 

 these monsters of the deep. The fibrous net-work of whalebone, 

 in the roof of the whale's mouth, is fitted to strain out these ani- 

 mals from the water which passes through and is ejected by the 

 spout-holes. Many minute dissections have been made of these 

 and other Crustacea, and some interesting physiological facts 

 brought to light. As the species are often transparent, nearly all 

 the processes of life, even to the motion of every muscle and ev- 

 ery particle that floats in the blood, are open to view. 



The Anatifa (a species of barnacle) has been traced through its 

 metamorphoses, from the young state when it resembles a Cypris 

 and swims at large with distinct compound eyes, to the adult ani- 

 mal ; and its connection with Crustacea is placed beyond doubt. 



The collection of corals at the National Gallery is one of its 

 principal attractions. The great beauty and variety of these pro- 

 ductions is not conceived of, even by those best acquainted with 

 other collections in our country. These are the material that 

 constitutes the immense reefs of the Pacific and East Indies — 

 some of which exceed a thousand square miles in extent. More 

 than three fourths of all the islands of this great ocean have been 

 built up through the labors of the coral animal. The formation 

 of these islands, and the growth of the coral animal, the filling 

 up and opening of harbors, and the rising of reefs — all interest- 

 ing subjects of discussion, received particular attention ; and the 

 number of coral islands visited, and reefs examined, have afford- 

 ed unusual opportunities for these investigations. Colored draw- 

 ings have been made of a large number of coral animals, which 

 will convey some idea of their singular beauty and richness of 

 colors. Many of these animals are wholly unknown to science, 

 as this is a branch of zoology to which comparatively little at- 

 tention has heretofore been paid, on account of the inaccessible 

 regions in which they occur. 



