208 The Microscope. 



the marks on our specimens, we may readily discover that one 

 bearing written characters must be a G^rammdtophora, and of 

 course, we recognize a letter in the S.-shaped Pleurosifpna ; and 

 that one with bands across it, like a ladder, must be a Climacos- 

 ■phxnia. If the bands give a wavy appearance to the sides, it 

 must be a Cymatopleura. 



Then there are some that look like wands, as in Bacillariay 

 and a Bacteriastrum, of course, is a stick bearing stars or rays. 

 The horny hairs of the Chetoceros, and the tubes of the Auliscua 

 distinguish them at once. If we want a buckle, we have one in 

 Porpeia; a little boat in Navicula; a sun-shield in Heliopelta ; a 

 shield with a boss in Omplialopjelta ; a little strap in Himantidium ; 

 a melon in Peponia, and a very ancient water-bottle with a nar- 

 row neck in Isthmia. 



If we notice flower-like forms in the sea foam, we recognize 

 Achnanthes, and that which resembles a " fan-shaped basket borne 

 upon the head in the feasts of Bacchus," is a Licmophora. In 

 the Triceratiuiii we do not alwaj's find three horns, but we dis- 

 cover a single eye in Monopsia. a cross in Stauroneis, a bow in 

 Toxonidea, rods in Rhabdoneiaa, an angular breast in 3Iastogonia ,. 

 and, possibly, a sea-urchin in Spatangydium. 



SrJtizoaeina, with tubes or threads massed into leafy or split 

 forms ; Encyonema, with its pregnant tubes, and CoUetonema, with 

 tubes or threads glued together, showing, as Van Heurck remarks^ 

 a transition between the preceding and Navicida, are good sub- 

 jects for controversy as to classification. We must not omit the 

 sociable Syndne, found sitting side by side in council. 



Our lexicon will not aid us in follov/ing Nitzschia, Biddidphia, 

 BrightwelUn, Duuhinia and many others, nor would u biographi- 

 cal dictionary be of an}" better service in the identification of 

 forms. They must be left to commemorate the services of Nitzsch,. 

 of Brightwell, of Donkin and other diatomists. Biddulphia is 

 said to have been named after a Miss Biddulph, of England. 



When we come to the determination of species, we must, of 

 course, change our Greek for a Latin lexicon, and while it may 

 seem startling to translate Coscinodiscus Oadus-Iridis as an " Iris- 

 eyed sieve plate," a glance at it under the microscope will scarcely 

 suggest a better name. From this short diversion, it appears 

 that the nomenclature of diatoms has been in worthy hands, 

 and has not suffered from much of the incongruity found in 

 other branches of botanical science. 



