DIATOMACE^E. 429 



might be simply dried and preserved just as found, and 

 the contents of the stomach afterwards obtained by 

 dissection. 



Noctilucae, which are the cause of phosphorescence in 

 the sea, are Diatom feeders, and might be caught in large 

 quantities in a fine gauze towing-net, and preserved. The 

 Ascidians found attached to oyster shells and stones from 

 leep water have yielded excellent gatherings. The Salpae 

 often noticed in warm latitudes floating on the surface of 

 the sea, and assuming chain and other like forms, should 

 be bottled up for examination. These Salpae are well 

 known Diatom feeders. Deep-sea soundings ought to be 

 preserved, especially from great depths, and are often 

 exclusively Diatomaceous. Sea-weed from rocks ought to 

 be preserved, especially the smaller species, and if covered 

 with a brown furriness, so much the better. Very rare 

 species have been found in immense quantities in the 

 arctic and antarctic regions, by melting the "pancake 

 ice" often found discoloured by these minute beings. The 

 sea is often observed to be covered by brownish patches. 

 The discoloured water (or " spawn" as it is called) should 

 be collected, filtered through cotton wool, and the 

 brown residue preserved. When a fine impalpable dust 

 is observed to be falling at sea, it ought to be collected 

 from the folded sails and other places where it lodges. 

 This may yield Diatoniacea?, which from the method of 

 collecting would be highly interesting to examine. The 

 roots of the various species of Mangrove (Rhizaphora), 

 which form impenetrable barriers along the salt water 

 rivers and estuaries in the tropical parts of Africa, 

 Australia, the Eastern Archipelago, &c, are found fre- 

 quently covered with a brown mucous slime very rich in 

 Diatomacese. When the Diatomacese are collected from 

 any of the above-mentioned sources, they may be at once 

 transferred to small bottles, or the deposit may be partially 

 dried and wrapped up in pieces of paper or tinfoil. 

 When placed in bottles, a few drops of spirits added will 

 keep them nice and sweet. In all cases it is essential to 

 keep the gatherings separate and distinct, and that the 

 locality whence obtained be written on each package. 



The collector will probably find that, notwithstanding 



