82 Rev. T. Hincks's Contributions towards 



Membranipora armifera, n. sp. (PI. XI. fig. 5.) 



Zooecia ovate, wholly membranous in front, margin smooth, 

 two spines at the top ; on each side, just below the upper 

 margin, an acute avicidarium standing out very prominently 

 and somewhat obliquely from the edge of the aperture ; the 

 mandible directed straight outwards. Ooecium (?). 



Loc. Gulf of St. Lawrence, on Flustra membranaceo-trun- 

 cata, Smitt (Dr. Dawson). 



Allied to the Arctic M. Sophice of Busk, from which it 

 differs in the character of the avicularium and the absence of 

 the lateral spines. The avicularia are placed horizontally 

 on the top of very prominent brackets rising from the margin 

 of the cell on each side, which are somewhat carinate in front. 

 The extremity of the acute mandible points outwards. Not 

 unfrequently there is a large raised avicularium at the base of 

 the cell. 



Membranipora horrida, n. sp. (PI. X. fig. 6.) 



Zooecia oval ; aperture occupying the whole of the front, 

 with a membranous covering, margins thin ; three or four 

 spines on each side, of which the uppermost pair are tall, stout, 

 and erect, the rest smaller, acuminate, somewhat bent in over 

 the aperture; a large avicularium at the bottom of the zooecium, 

 placed transversely, and usually extending some way up one 

 side of the cell, very slightly raised; mandible elongate, lingui- 

 form, occasionally replaced by a small avicularium with short 

 mandible. Ooecium rounded, smooth, with an arched rib in 

 the front. 



Loc. California (Miss Jelly) . 



The marked character of this species is the large lingui- 

 form avicularium at the base of the cells ; it has a tendency, 

 however, to revert to a smaller and more usual form. 



Membranipora Carteri, n. sp. (PL XI. fig. 8.) 



Zooecia membrano-calcareous, ovate, wide and patulous, 

 suberect, disposed in linear series ; margin thin and smooth, two 

 very stout clavate spines at the top, and two somewhat 

 smaller placed one on each side about halfway down the 

 cell. Avicularia sparingly developed, capitate, articulated, 

 rounded behind (not elongate), with a short slightly bent 

 beak ; placed on one side of the cell, immediately below the 

 spine at the top. Ooecium (?). 



Loc. Australia, incrusting weed (Mr. IT. J. Carter). 



This form has a special interest, as being the only known 

 Membranipora which possesses a fully developed bird's-head 



