168 Rev. T. Hincks’s Contributions towards a 
Mucronella prestans, n. sp. (Pl. VII. fig. 1.) 
Zoecia ovate, quincuncial, often much expanded below, 
front wall rather depressed, strongly areolated round the 
margin, the central portion smooth or traversed by the pro- 
longed radiating furrows of the areola; surface very bright 
and shining; orifice suborbicular; peristome carried up in 
front into a neck-like prolongation of considerable length, 
which often rises into a point in the centre (occasionally 
bimucronate), the lip somewhat everted and frequently 
much thickened, at the sides sloping off towards the upper 
margin, which is not elevated and bears four spines ; on one 
side of the cell, attached to the neck-like elevation of the peri- 
stome, and directed outwards, or sometimes placed lower on 
the cell and sloping obliquely downwards, a large spatulate 
avicularium, raised on a kind of bracket, the walls of which 
are perforated. Ociwm rounded, rising rather steeply to- 
wards the centre, somewhat prolonged and contracted towards 
the orifice, strongly areolated round the base ; central portion 
smooth and shining, more or less traversed by the areole, 
mucronate. | 
Loc. New Zealand, recent, and from later Tertiary beds 
(Miss Jelly). 
This is without question one of the most attractive of its 
tribe, its remarkable beauty being due to the exquisite border 
formed by the areolation round the cells and the brillianey of 
the vitreous surface. ‘The oral operculum seems to be com- 
posed of a thin almost membranous material. The raised 
peristome projects very considerably, and is commonly carried 
out to an acute point; frequently, however, it is broader in 
front; and the margin is often much thickened. There is some 
variability in the position of the avicularium ; but it is usually 
placed against the neck of the cell or at the base of it. 
Mucronella rotundata, n. sp. (Pl. VIII. fig. 5.) 
Zoecia quincuncially arranged, with a more or less rounded 
outline, short, tumid, suberect, separated by deep sutures ; 
surface smooth or slightly pitted over ; orifice of (proportion- 
ally) large size, arched above, straight below, a central bifid 
tooth and two minute lateral denticles placed very close to it 
within the lower margin ; peristome elevated round the sides 
and in front, where it is carried up into a central mucro of 
moderate size; on the upper margin four slender spines. 
Avicularia none. Occium (2). 
Loc. Singapore or Philippines (J/iss Jelly). 
This has much the appearance of a distinct form, though in 
