50 Objects for the Microscope. 



ASTEKOMPHALUS ASTEROLAMPRA, 



From aster (a star), omphalos (the navel), and lampra (shining). 



Look for these in the slides of fossil guano, Bermuda 

 earth, Virginia deposit, and Piscataway earth. They present 

 beautiful umbilical rays, reaching only halfway towards the 

 margin, and alternate rays proceeding from the margin, 

 forming a bright star in the centre, having five areolae in 

 each marginal division. 



COSCINODISCUS, 



From, coscinon (a sieve), 



has no rays or divisions, but resembles the Indian turn of a 

 fairy watch. The structure is wholly cellular, and the 

 species, of which there are forty, are known one from 

 another by minute yet regular markings, tubercles, and 

 variations in the size of the cells. They are found alive in 

 the sea off Cuxhaven ; fossil in the Richmond, Virginia, and 

 Bermuda earths, also in the chalk marl of Oran. 



These are the specimens most commonly sold by opti- 

 cians, and they show us what DiatomaceaB are ; but to 

 pursue the study, and learn the myriads which a little 

 bog-water or a spray of seaweed would reveal, we must 

 read Pritchard's work on Infusoria ; or, if further interested 

 in the manner of their propagation, which is really won- 

 derful read the article "Diatomacea" in the works on 

 the Microscope by Carpenter or Hogg. 



DESMIDIACE^E. 



These are minute plants, of green colour, found in fresh 

 water, shallow pools, and ditches. 



YOLVOX GLOBATOR. 



This is one of them, which, from its animalcule-like 

 movement and extreme beauty, has long been considered 

 as one of the Infusoria. If mounted, it maybe beautiful, 

 but is much more so in its living, moving state, in a drop 



