256 Rev. T. Hincks's Contributions towards a 



outwards, constricted a short distance above it, opercular 

 denticles prominent ; peristome not elevated, unarmed. On 

 one side of the orifice, about halfway between the upper and 

 lower margins, an avicularium, with shallow subtriangular 

 mandible, directed outwards. Ooecium (?). 



Loc. Trincomalee (own collection). 



The avicularium of this species is furnished with a shallow 

 mandible, which is blunt above, and has much the appearance 

 at first sight of being semicircular ; it is, however, correctly 

 described as subtriangular. 



The large size of the cells and the flat surface are character- 

 istic points. 



Lepralia vestita, n. sp. (PI. IX. fig. 9.) 



Zoozcia ovate, quincuncial, convex (sutures rather deep), 

 surrounded by a very slight interstitial line, completely in- 

 vested with a glossy brown epidermis, beneath which the 

 surface is white and granular (the granules show as indistinct 

 spots through the epidermis) ; orifice taller than broad, arched 

 above, the lower margin curved outwards, a slight constriction 

 immediately above it ; peristome much elevated round the 

 orifice, suberect (forming a kind of shaft), margin white, thin, 

 unarmed ; on one side of the orifice or on both sides a pointed 

 avicularium, leaning against the peristome and directed ob- 

 liquely upwards. Oozcium rounded, very broad, moderately 

 convex, placed behind the subtubular peristome, and covered 

 by the shining epidermis. 



hoc. Tahiti (Miss Jelly) ; Fiji Islands, on Pinna (own 

 collection). 



In a young state the cell is covered with minute punctures. 



Lepralia Poissonii, Audouin. 



Two forms of this species occur ; in one the vibracula are 

 situated below the orifice and are placed horizontally, in the 

 other they are vertical and placed at the side of the orifice 

 near the top of it and close to the margin. There are also 

 slight differences in the ooecium, but they are unimportant. 

 In a specimen from the New-Zealand Tertiaries the orifice is 

 very small and the vibracula are placed a good way down the 

 cell, with a prominent central umbo between them. In the 

 original figure by Savigny the vibracula are represented below 

 the orifice, and the ovicells as traversed by lines (? ridges) 

 radiating from the top towards the opening. These varia- 

 tions are interesting, but have no special significance. 



There are as many as from twelve to fourteen of the tall 

 slender spines round the base of the cell in perfect specimens. 



