16 



POLYZOA. 



Family VI. Membeanipoead^. 



Memhranipora (Jolinst.). Cells open in front, 

 with raised margins ; usually encrusting sea- weeds, 

 more rarely shells and stones. 



M. membranacea. M. riemiiigii. 

 pilosa. Fig. 25 ; n. s. and mag. Rosselii. 



coriacea. Lacroixii. 



lineata. monostachys. 



25 



26 



Lepralia (Johnst.). Cells closed in front, spread- 

 ing from the centre outwards. 



N.B. The British species of this genus, which 

 are very numerous, are thus subdivided \>j Mr. 

 Busk : — 



* Furnished with birds'-heads. 



a. Bii-d's-head medial and single, 



a. Above the mouth. 



L. Brongniartii. 



b. Below the mouth. 



L. Landsborovii. L. concinna. 

 reticulata. verrucosa, 



auriculata. violacea. 



/3. Birds'-heads double ; or if single, on one side. 

 L. spinifera. L. coccinea. 



trispinosa. linearis. 



