88 MOLLUSCOIDA 



9. Put powdered carmine in the water with a living branch 

 and see if the zooids will eat it. 



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 ex- 

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

 power, to good advantage. 



Study specimens that have been killed while expanded. 

 Stain with iodine, 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 posi- 

 tion 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 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. 



Bissonnette: A Method of Securing Marine Invertebrates. Science, 



71, 1930. 

 Grave: Natural History of Bugula flabellata. Jour. Morph., 49, 1930. 



PLUMATELLAi 



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 epistome. 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 

 statoblasts with a microscope. 



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

 Calvet : Contribution a l'Histoire Naturelle des Bryozoaires Ectoproctes 

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



Alices 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. 



