INVERTEBKATA, CRYPTOGAMIA, MICROSCOPY, ETC. 591 



8. Cldamydomonadina. 



Polytoma ; Cblamydomonas ; Cblamydococcus ; Phacotus ; 

 Coccomonas ; Tetraselmis ; Goniuin. 



9. Volvocina. 



Eudorina ; Paudorina ; SteiiLanosplifera ; Volvos, 



10. Hydromorina. 



Chlorogonium ; Chloraugium ; Pyramidomouas ; Chloraster ; 

 Spondylomorum, 



11. Cryptomonadina. 



Chilomonas ; Cryptomonas ; Neplirosolmis. 



12. CMoropeltidea. 



Cryptoglena ; Chloropoltis ; Pliacns. 



13. Euglenida. 



Euglena ; Colacium ; Ascoglena ; Traclielomonas. 



14. Astasicea. 



Eutropia ; Astasia ; Heteronema ; Zygoselmis ; Pcrancma. 



15. Scytomonadina. 



Scytomonas ; Petalomonas ; Menoidium ; Atractoiiema ; 

 Phialonema ; Spenomouas ; Tropidocyplins ; Auisonema ; 

 Colponema ; Eiitosiplion. 



Stein places Volvox, Eudorina, Pandorina, Euglena, and even 

 Chlamydococcus pluvialis amongst the Flagellate Infusoria, on tlie 

 ground principally of tlie presence of a contractile vesicle. His 

 observations on tbe multiplicity of Volvox and analogous genera 

 confirm tbose of Cobn. 



Stein accepts tbe views of Clark on tbe nature of sponges, and 

 gives figures of a great number of new species of Infusoria discovered 

 by bim, wbicb seem to establisb incontestable links between tbe 

 Flagellate Infusoria and tbe true sponges. 



He does not appear to bave verified or even to bave known of tbe 

 observations of Dallinger and Drysdale on tbe life-bistory of 

 Monads. 



Effect of Light on Pelomyxa.* — In a very low, amoeba-like 

 organism, Pelomyxa pfl7«s^r/s, Herr Engelmann recently observed a 

 remarkable action from sudden incidence of a moderate ligbt. 

 Watcbed in tbe Microscope, tbis organism sbowed very slow move- 

 ments, wbicb, bowever, on sbading tbe object, became mucb more 

 lively. Wben tbe band was removed tbe glandular mass in tbe 

 interior became still, and tbe body contracted into a ball, as after an 

 electric sbock ; tbis effect occurred witbin a few seconds. Witb 

 continued moderate ligbt, weak cbauges of form appeared again, witb 

 bardly perceptible locomotion. Tbis experiment was several times 

 repeated witb equal success, and tbe results were especially notable in 

 a dark room, into wbicb diffused dayligbt could be admitted. Wben, 

 however, tbe room was illuminated — not suddenly, but gradually — 

 tbe Pelomyxa sbowed no effect. 



* ' Arch. f. P]iy.s.' (Pfliiger), xix. (187D) p. 1 ; ' Nature,' xx. (1879) p. 100. 



2 R 2 



