MEMORANDA. 



105 



Amphora ovalis 

 „ saliua 

 „ areuaria 

 Arachnodiscus oruatus 

 Aulacodiscus orieutalis 

 Berkeleya fragilis 



„ Dillwynii 

 Biddulphia pulchella 

 Campylodiscus clypeus 

 Cerataulus turgidus 



„ Isevis 



Ceratoneis arcus 

 Chaetoceras armatum 

 Coccoueis pediculus 

 „ scutellum 

 „ Grevillei 

 Coscinodiscus ompbalanthus 

 *Cyclotella rectangula 

 Cymatopleura apiculata 

 Cymbella gastroides 

 *Denticula obtusa 



* „ therraalis 

 *Diatoma grande 



„ hiemale 

 Donkinia carinata 

 *Eiicyonema prostratuin 

 Endosigrna eximium 

 Epithemia turgida 

 ai-gus 

 „ sorex 



* „ constricta 

 Eunotia pectinalis 



„ undulata 

 Eragilaria virescens 

 „ mesolepta 



* „ minima 



* „ Harrisouii 

 Gomphonema teuellum 



„ acuminatum 



„ geminatura 



Grammatophora marina 



*Melosira nummuloides 

 Navicula nobilis 



„ oblonga 



,, lata 

 *, Brebissouii 



„ cryptocephala 



„ affiiiis 



„ serians 



„ sphasrophora 



„ cuspidata 

 Nitzschia obtusa 



* „ Palea 

 „ tenuis 



* „ lanceolata 

 „ Closterium 



Orthosira Roeseana 



* „ Dickieii 

 „ areuaria 



Pleurosigma strigosum 

 „ balticum 



„ attenuatum 



„ acuminatum 



Rhabdonema arcuatum 

 Rlioicosplienia curvata 

 Scbizouema Grevillei 

 *Scoliopleura tumida 

 Slauroneis Phoenicenteron 

 Striatella unipunctata 

 Surirella biseriata 

 „ gemma 

 „ ovata 

 *Synedra pulchella 

 Vaucherise 

 splendens 

 afSnis 

 „ fulgens 

 Tabellaria flocculosa 

 Terpsinoe musica 

 *Tetracylus lacustris 

 Triceratium arclicum 



* 



» 



Test-Diatoms — When one speaks of " test/' how is it 

 possible that Navicula affinis and N. rhomboides can be con- 

 founded ? These diatoms do not resemble each other in any- 

 way, either in form or in the fineness of their strise. 

 Navicula afinis is always distinguished by the line or nervure 

 which runs along the margins of the valve, which is gently 

 contracted towai'ds its extremities, and the ends of which are 

 rounded off. The strise, though difficult to resolve, are much 

 less closely packed (46" 60 in -001") than those of N. rhom- 

 boides. Different authors, however, have described and drawn 



VOL. VIII. NEW SER. H 



