()2 MARINE POLYZOA. 



Lacroixii, to which, in the older state especially, it bears an ex- 

 tremely close resemblance, seems nevertheless to me to be quite 

 distinct. It usually forms a delicate gauze-like coat upon shells 

 and stones, and is then quite calcareous, though very delicate 

 and thin ; but it also occurs in a more membranaceous condition 

 and growing in an irregular foliaceous form of a greenish colour 

 (dry). The only specimen of this sort that has come under my 

 notice was kindly furnished by Dr. Landsborough ; it was found 

 by Mr. Higham of Norwich in brackish water and in considerably 

 sized masses. It can hardly, perhaps, be regarded as purely a 

 marine form, and will be found I imagine more abundantly in 

 rivers near the sea, or in shallow estuaries, than in the sea itself. 

 It occurs in great plenty on shells and stones on the muddy 

 bottom of the river Deben in Suffolk. I have also a specimen 

 very like this species from St. Vincent, one of the Cape de Verde 

 Islands. 



15. MEMBRANIPORA MAGNILABRIS, n. s. PI. LXV. fig. 4. 



Front of cell oval ; upper margin semicircular, much raised ; 

 moveable lip very large, occupying the entire semicircular upper 

 third of the front of the cell , remainder of the front of cell de- 

 pressed, membranous or semicalcareous, punctured. 



Hab. Abrolhos Islet (Atlantic), Darwin. Algoa Bay, BowerbanJc. 

 On shell. 



Very remarkable for the large size of the cells and the very 

 great dimensions of the moveable lip ; this part, as usual, is com- 

 posed of a semicircular rim of horny matter ; but besides this, 

 the membrane stretching across the semicircle is further supported 

 by two slender bars of horny substance, which extend from the 

 side of the base to the centre of the bow, where they meet. This 

 species might be regarded as the type of the cheilostomatous 

 Polyzoa, and from its comparatively large size would probably be 

 an interesting subject for examination in the living state. 



16. MEMBRANIPORA GALEATA, n. s. PI. LXV. fig. 5. 



Front of cell oval ; two pointed marginal spines on each side, 

 towards the top. Ovicell galeate, widely open beneath, crowned 

 with a large oblong avicularium. 



Hab. East Falkland Islands, 4 to 10 fathoms, Darwin. OnLa- 

 minaria. 



Colour dark purple. 



