NO. 1933. BBYOZOA FROM EASTERN NORTH AMERICA— OSBURN. 289 



1869. Whiteaves, J. F. On some results obtained by dredging in Gaspe and off 



Murray Bay. Canadian Naturalist, pp. 1-4. 

 1874. ■ . On recent deep-sea dredging operations in the Gulf of St. Lawrence. 



American Journal of Science and Arts, vol. 7, March, 1874, pp. 1-9. 

 1901. . Catalogue of the Marine Invertebrata of Eastern Canada. Geological 



Survey of Canada, Ottawa. Polyzoa, pp. 91-114. 



EXPLANATION OF PLATE 34. 



Fig. 1. Cellepora contigua, showing a young cell without avicularium at edge of colony 

 and more fully developed cells with avicularia. 



2. Lepralia spathulifera, mature cell denuded of spines and central avicularium. 

 2a. The same, showing central avicularium and spatulate spine and central avicu- 

 larium (more enlarged) with open mandible. 



26. The same, showing variations in form of spatulate spine. 



3. Mucronella prxlucida, infertile cell with aviculariimi. 



3a. The same, showing fertile cell, ovicell, and lateral spaces where avicularia 



have failed to develop. 

 3c. The same, showing avicularium with a partially detached mandible. 



4. Porella saccata, aperture and oral avicularium seen partially from in front, 



drawn to the same scale as fig. 5a. 



5. Porella perpusilla, cross-section of rounded stem showing manner of calcifi- 



cation. 



5a. The same, aperture, oral avicularium and denticles, drawn to the same scale 

 as fig. 4. 



56. The same, details of young cells with ovicells in different stages of develop- 

 ment. 



The figures are from camera lucida drawings by the author. 



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