LUCINID&. 155 
right, and the hinder of left valve the smaller ; lateral teeth elongate, 
smooth, compressed, of right valve double, of left valve simple ; liga- 
ment external. 
P. novee-zealandie, Prime, P.Z.S., 1862, p. 3; P. novo-zea- 
landicum, Prime, Ann. Lyceum of Nat. Fiist., New York, 1867, p. 91. 
Shell minute, transverse, oval, sub-oblique, very inequilateral, rather 
compressed, thin ; the anterior side produced, elongated and rounded, 
the posterior sub-truncated ; umbones small and obtuse; epidermis 
yellowish-horn colour and polished (Prime.) 
Length, ‘16; height, ‘12; thickness, ‘o8 inch. 
New Zealand. (Cuming.) 
Sub-Order—Lucinacea. 
Mantle lobes free beneath, united posteriorly, forming a separate 
siphonal opening ; gills one on each side; foot cylindrical, elongate, 
inferior ; anterior adductor muscle usually elongate. 
FAMILY—LUCINID.. 
Labial palps small and rudimentary. Mantle lobes free beneath, 
furnished behind with one or two sessile siphonal apertures ; gills one 
on each side, large, oval, thick. Foot cylindrical, elongate, inferior, 
usually hollow throughout its entire length, the tube opening into the 
spaces of the visceral cavity. Shell orbicular, free, closed ; hinge teeth 
one or two, laterals + or obsolete ; pallial line simple ; muscular impres- 
sions elongated, rugose ; interior dull, obliquely furrowed. 
Genus, -LUCINA—Bruguiere. 
Siphonal orifices simple, without a prolonged anal tube ; white ; um- 
bones depressed ; lunule distinct ; ligament semi-internal ; anterior mus- 
cular impression elongated within the pallial line ; posterior oblong. 
L. divaricata, Zamark, Anim. sans vert., Vi., p. 2263; Reeve, 
Conch. Ic., f- 47a; Chenu, f. 572. Orbicular, sub-globose, with thin 
undulating bifarious strie, margin even, no lateral teeth. 
Heigth, 1°12 ; length, 1°25. 
Auckland to Chalky Sound. Chatham Islands. ‘Tasmania. 
FAMILY—UNGULINID&. 
Mouth with four foliaceous, membranous palps. Mantle margins 
united, with the exception of a large inferior pedal opening, and a small 
sessile anal aperture. Gills two pairs on each side, united behind. Foot 
vermiform, ending in an erectile gland, channelled throughout its length. 
Sub-orbicular, closed ; hinge of two diverging bifid cardinal teeth, with- 
out laterals ; ligament marginal. 
L. lactea, A. Adams, P.Z.S., 1855, p. 225, (nec Lamark). Shell 
thick, orbicular, sub-ventricose, milk-white, concentrically lamellated ; 
