PLATE 2. 



Fig. 31. Hydra viridis. 



,, 32. ,, (end of a tentacle). 



,, 33. ,, (transverse section of the body). 



,, 34. ,, (ditto, more highly magnified). 



,, 35. ,, (an exploded nematocyst). 



,, 36. Cercaria, a larva of a Distomea. 



37. Amphistomum (Diplodiscus) subclavatus. 



38. A Nematode. 



,, 39. Nais proboscidea. 



40. Tubifex rivulorum. 



41. Glossiphonia (Clepsine). 



,, 42. Sphaerium. 



,, 43. Limnaea palustris. 



44. ,, (egg capsule). 



45. Ancylus. 



46. Planorbis. 



47. (egg capsule). 



,, 48. Simocephalus vetulus. 



,, 49. Ceriodaphnia reticulata 



50. Chydorus sphaericus. 



,, 51. Alona quadrangularis. 



52. Cypris. 



,, 53. Cyclops. 



54. Nauplius larva. 



55. ,, (older stage). 



56. Canthocamptus minutus. 



57. Cloeon (larva). 



58. Cloeon (imago). 



59. Libellula depressa. 



60. Corixa Geoffroyi. 



,, 61. Hydrometra stagnorum. 



(N.B. During the process of reproduction the figures have been 

 reduced by l-20th.) 



