G. TUBULARIA. 99 



TRAILING. 



2. Naisa reptans. Tubes membranous, transpa- 

 rent, branching, and much larger at the base than at 

 the summit. — Plate 6. fig. 4. A. 



In fresh water. 



LIGHT-SHUNNING. 



3. Naisa lucifuga. Tentacula retreating within 

 the tube, ciliated at their edges, from twenty-five to 

 thirty-two in number; ramifications numerous and 

 horizontal ; interior beads round and flat, and opening 

 parallel to the body on which they rest. — Plate 6. 

 fig. 5. A. 



campanulated. 



4. Naisa campmiulata. Stem filiform, and alter- 

 nately branching ; orifice of the tubes marked with 

 rings. 



In stagnant waters. 



SULTANA. 



5. Naisa sultana. In a funnel-shaped tuft, cilia- 

 ted at the base ; tentacula twenty in number, and 

 pointed. 



In the fresh waters in the vicinity of Gottingen. 



TUBULARIA. 



PoLYPiDOMS simple or branching; tubular, of a 

 substance almost horny, and transparent ; a solitary 

 polypus at the extremity of each branch, with two 



