66 MOLLUSCOTDA. 



10. Put a small living branch in a drop of sea-water under 

 a supported cover-glass and see if any of the zooids will expand. 

 If any do expand they may be examined, with a high powei, 

 to good advantage. 



Study specimens that have been killed while expanded. 

 Stain with iodin, wash in water, mount in glycerin, study with 

 a high power. Find the retractor muscles, the funiculus, germ 

 cells, and, if possible, the shape of the alimentary canal As 

 the alimentary canal bears a definite relation to the position 

 of the zooid on the branch, its shape can be readily determined 

 only when the branch happens to be twisted so the zooid is 

 to be seen in side view. 



Make a drawing showing the structure. 



If time permits study Flustrella, Membranipora, Lepralia, 

 or Schizoporella, as type incrusting forms to determine methods 

 of branching, colony formation, how the apertures are closed, 

 and specific characters. 



PLUMATELLA.i 



If the zooids of this fresh-water form will expand in a watch- 

 glass of fresh water, notice the shape of the lophophore and the 

 position of the epistame. In such a specimen the ganglion may 

 be seen as a rounded mass just beneath the lophophore, between 

 the mouth and the anus. Study the statohlasts with a microscope. 



Allman: Monograph of the Fresh-water Polyzoa. Ray Soc, 1856. 

 Calvet: Contribution al'Histoire Naturelle des Bryozoaires Ectoproctes 



Marins. Trav. Inst. Zool. Montpelier, N. S., Mem. No. 8, 1900. 

 Nitsche: Beitrage zur Kenntnis der Bryozoen. Ueber die Anatomic imd 



Entwicklungsgeschichte von Flustra membranacea. Zeit. f. Wiss. Zool., 



21, 1871. 

 O'Donoghue, Charles H., and Elsie O'Donoghue: Second List of Bryozoa 



from Vancouver Island Region. Contrib. to Canadian Biol, and 



Fisheries, N. S. Ill, pp. 47-132. (See Bibliography list, 1926.) 

 Osburn, T. C: Bryozoa of Woods Hole. Bui. Bureau of Fisheries, xxx, 



1910, Doc. No. 760, 1912. 



1 Slices of the large gelatinous form, Pectinatella, placed in watch- 

 glasses of fresh water, make very satisfactory objects for study, as the zooids 

 will soon expand, and they are then in the best possible position for study. 



