Group of Various Diatoms. A superb 'circle of Diatoms'. Made for Watson & Sons dating from between 1882 - 1908. Price includes international shipping. £350

Exhibition slide produced by Robert Isaac Firth.  Mid c20th A fine arrangement of Diatoms in an artistic pattern. According to Bracegirdle "His mounts are of the highest quality and much sought-after". Price includes international shipping. £350

Exhibition slide of arranged Spicules of Glass-rope sponge Produced by William Allott Firth. c.1880. A fine arranged group of spicules from the Gorgonia holothuria sponge.'Exhibition' slides of this type show off the prowess of the mounter. The general opinion is that they are of little scientific value, however they are a testament to the patience and skill of the individuals who laboured to produce them.Always desirable slides to have in any collection and much sought after.Price includes shipping. £150 ...

 Exhibition group of Various Diatoms Approx. 140 Diatoms from the famous Oamaru deposit in New Zealand. A superb and neat circle of specimens. Produced for W.Watson & Sons between 1882-1908. 'Exhibition' slides of this type show off the prowess of the mounter. The general opinion is that they are of little scientific value, however they are a testament to the patience and skill of the individuals who laboured to produce them.Always desirable slides to have in any collection and much sought after.Price includes shipping. £500 ...