248 Rev. T. Hincks's Contributions towards a 



Family Membraniporidae. 

 Membranipora, De Blainville. 



Membranipora valdemunita, n. sp. (PL VII. fig. 2.) 



Zocecia pyriform, quincuncial, of a delicate vitreous material, 

 area occupying more than three fourths of the front, elongate- 

 oval, wholly membranous, with a slightly thickened and 

 crenulate margin, on each side a little below the top a 

 single spine, cell produced below the area, and on this portion 

 of it a prominent central knob or (occasionally) two, one on 

 each side. Ooecium rounded, surface smooth, a subtriangular 

 space in front bounded by raised lines, a median line passing 

 from the centre of the oral arch backwards. Avicularia dis- 

 tributed amongst the cells and replacing them, occasionally 

 about as large as the cell, usually much smaller, elongate, 

 narrow, subspatulate, margin thin and elevated round the 

 sides and anterior extremity ; a strong denticular process on 

 each side at the origin of the mandible. 



Loc. Napier, New Zealand (Miss Jelly). 



In many cases the produced portion of the cell below the 

 area is wanting, or nearly so, and it then appears simply 

 elongate-oval in form, butnormally it would seem to be distinctly 

 pyriform, as stated in the diagnosis. The avicularia are gene- 

 rally placed singly, but sometimes occur in clusters of three. 



Membranipora titans, n. sp. (PI. VII. fig. 5.) 



Zocecia quincuncial, short, arched and contracted above 

 expanding slightly downwards, or subquadrate, sides much 

 elevated, minutely granular, margin thin, not beaded, on 

 each side, at the top, a stout spine ; front wall wholly mem- 

 branous, oral valve very large, arched above, straight below, 

 bordered by a chitinous edging, and with a broad membranous 

 expansion round the upper part of it ; on the lower margin of 

 the area a broad slightly projecting lobe bearing numerous 

 minute spines or prickles, enclosed by the membranous wall. 

 At the base of the cells (on an intercellular space) a pointed 

 avicularium (sometimes two) borne on a prominent umbo. 

 Ooecium massive, very much broader than high, with a wide 

 and shallow oral arch ; surface uneven, often bearing one or 

 two pointed avicularia. 



Loc. New Zealand {Miss Jelly). 



In this species the wall surrounding the area is much ele- 

 vated, and the membranous covering appears depressed. There 

 is a peculiarity in the oral valve ; it is placed some way 



