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 campanulata. 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 
