BRYOZOA OF THE GEORGIAN BAY REGION 197 



SESSIONAL PAPER No. 39b 



variety. The statoblasts of this species are very abundant in well developed 

 colonies. It has been found at Go Home, Skerryvore, French River, Killarney, 

 Fitzwilliam Island, and Tobermory. 



Habitat. — This species is found chiefly under the leaves of water-lilies and 

 other plants, on sticks, stones, and old iron, in ponds and sheltered bays, sometimes 

 exposed to the direct sunlight. The colonies appear first from the middle to the 

 end of May. The first colonies are found chiefly on twigs and bark, since the leaves 

 are not yet developed. They do not seem to avoid the light and the twigs offer 

 almost no shade. About a month later the colonies are fully developed, and soon 

 afterwards disappear. At this stage the statoblasts are exceedingly abundant, 

 and numerous embryos may be seen swimming about. These soon develop into 

 small colonies, and during the latter half of July and in August these are in many 

 places found in great abundance under water-lily leaves. 



Brown bodies are very abundant in older colonies, especially of the first gener- 

 ation, shortly before "it disappears. The branches of the colony usually contain 

 .Chironomus larvae, which devour the cuticula. In some cases swarms of unicellular 

 organisms may be seen in the zooecia. This species was common at Go Home, 

 both in 1911 and 1912. 



Plumatella fungosa (Pallas), {=P. polymorpha, vax. fungosaKv&epelm). 



The statoblasts of this species are more elongated than those of P. repens. 

 Davenport gives the limit of the varieties of P. repens as 1 : 1 • 5 ; but specimens 

 from Georgian Bay are often more elongated, the proportions being as high as 1: 

 1 '65. The lower limit of the statoblasts of P. emarginata is given as 1 : 1 '53, thus 

 overlapping with this species; but this does not prevent the identification of the 

 species by means of the statoblasts, since many of those of P. fungosa are quite 

 round, specimens with the proportions of 1 : 1*2 being found. 



This species occurs at Waubaushene, Go Home, Skerryvore, French River, 

 Killarney, Club Island, Tobermory, and McGregor Harbor. 



The habitat of this species is on leaves of pond weeds, water-lilies and sticks. 

 It coats leaves of pondweeds (Pontederia) and is thus somewhat exposed to sunlight. 

 It is found in still water or only moderately exposed to waves. Brown bodies and 

 statoblasts very abundant in older colonies. Like P. repens, this species is some- 

 times found in dense masses, with strings of tubes extending out two and a half 

 inches, or more. They are found in almost incredible numbers during the latter 

 part of July in Matchedash Bay, near Waubaushene, coating the pondweeds which 

 clog the bay. From July to September. Not rare in 1911 or 1912, but found in a 

 number of places in 1912, where they were absent in 1911. The form is rather 

 constant throughout the season, except for the changes due to crowding. 



Plumatella appressa Kraepelin. (=P. polymorpha var. appressa Kraepelin). 



Cuticula transparent to brown, coriaceous; tubes flattened, closely adherent 

 to the substratum, and seldom rising from it. There is usually a clear longitu- 

 dinal band, or a low keel. The branching is angular. The fixed statoblasts^ are 

 abundant in this species, and may be seen adhering to the under sides of the flat 



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