20 DIATOMAOB : v.. 



desirable to study the geographlca] distribution of the diatom- 

 acear, and then mixed gatherings become of value as exhibiting 

 the number of forms occurring at a particular station. Then, 

 again, the fossil as well as the semi-fossil deposits and guanos 

 may be cleaned and mounted as obtained; but even then it may 

 become desirable, if space can be spared in the cabinet, to have 

 the various species found in each gathering separately mounted, 

 so that they may be at any time studied in comparison with 

 similar forms from other localities. 



General directions for collecting diatomacere have been 

 already given in the preceding chapter; but it will be desirable 

 to again allude to a few points in connection with this portion 

 of our subject. Some years since, an article entitled " Hunting 

 for Diatoms" was published in a London journal called The 

 Intellectual Observer. The author's name was not given, but 

 internal evidence would seem to indicate that it was penned by 

 a deceased botanist of note, who was a decided authority on 

 this branch of biology. This paper contaius some valuable 

 hints respecting the places in which to look for diatoms, and 

 some of the suggestions contained therein I have ventured to 

 transfer to these pages, as they will be found of value to the 

 intending diatomist. Thus, the exquisite Ar<icl/n<>idiscus, 

 Triceratium Wilkesii, and Aulocodiscus Oregonensis, may be 

 looked for on logs of wood which have been floating in the 

 sea, and imported from New Zealand or Vancouver's Island. 

 So, on logs from Mexico and Honduras may be found the curi- 

 ous Terpsinaz music* t. The nets of fishermen, especially from 

 deep water, may yield algas bearing such forms as Rhabdonema 

 arcuatum or Adr latum, (jrrammatophora serpentina and marina, 

 various Syuedras, and other fine forms. On oyster shells may 

 be found algaa bearing upon their fronds Biddulphia reginfi^ 

 BaUeyii or aurita. Rhizosolenia styliformis is said to be almost 

 sure to be there likewise. After a ship is unloaded, and as it 

 floats higher in the water, its sides may be searched for treasures 

 of the diatom world, and Achnanihes longipes and brevipes 

 found, or even Diatoma hyalinum and Hyalosira delicatula. The 

 sea grass, or Zosters marina, growing along our coast, often 

 bears upon its waving ribbons fine forms of diatoms, and that 

 used for stuffing chairs, and lounges or mattresses, and im- 



