216 THE ROYAL SOCIETY OF CANADA 



EXPLANATION OF DRAWINGS. 

 Plate I. — Colon- Aerogenes Group. 



Surface Colonies. 



1. Small, round black, surface smooth, margin entire, raised, medium blackened. 

 There was considerable difference in intensity of field. In some cases field 



was so faint that it was hardly visible. 



2. Small, round, black centre, periphery brown, surface smooth, margin entire 



raised, medium blackened. 



3. Large, slimy, round, dirty grey, periphery brown, margin entire, raised, medium 



blackened. 



4. Large, slimy, round, brown, surface smooth, margin entire, raised, medium 



browned. 



5. Large, slimy, round, dark grey, margin entire, raised, medium browned. 



Deep Colonies. 



6. Small, round, black, margin entire, medium blackened. 



7. Small, round, brown, margin entire. 



8. Small, round, black, margin entire, light brown halo. 



9. Small, elliptical, red brown, margin entire. 



10. Small, elliptical, black, margin entire, medium browned. 



Plate 2. 



293, 152, 381, Surface colony. Large, round, colourless, watery, margin entire, 

 surface smooth, light brown field surrounded by a halo of black crystals. 

 Deep Colony. Small, round, black, no fields but the colony is surrounded by a 

 halo of black and white crystals. 



171, 174. Surface colony. Large, round, watery, bluish white, faint brown field. 



Deep colony. Small, black, lenticular, faint brown field. In the field appear 



large numbers of white crystals. 

 175. Surface colony. Large, round, watery, colourless, black centre, field black. 



Deep colony. Small, black, lenticular, field black. 

 358. Surface colony. Large, round, watery, colourless, red-brown centre, field 



transparent red brown, which in turn is surrounded by black field. 



Deep colony. Punctiform, black, field black, some black crystals. 



Note. — No attempt has been made to indicate the intensity of the colouring of colonies 

 and fields, there being a considerable variation in colonies of one and the same 

 organism. 



Plate 3. 



109. Surface colony. Large, round, colourless, red-brown centre, field black brown. 

 Deep colony. Small, black, halo of black crystals, no field. 



294. Surface colony. Small, round, watery, black centre, field light brown. 

 Deep colony. Punctiform, black, halo of white crystals, no field. 



441. Surface colony. Round, dirty white, faint black field. 



Deep colony. Sm.all, lenticular black, faint black field. 

 HI. Surface colony. Large, round, slimy, brown, field black. 



Deep colony. Small, lenticular, black, field black. 



