AVICULID&. 169 
drical, thin, short, and roundly truncated in front, contracted in the 
middle, and rather produced and tapering behind, covered with a dark 
brown periostraca; umbones rather prominent, inflexed; inner side 
purplish, rather pearly (Gray). 
Auckland ; rare in the south. 
L. gruneri, Reeve, Conch. Ic. f. 12. Shell acutely elongated, 
peculiarly angularly gibbous about the umbones, attenuated anteriorly ; 
dark chestnut, obliquely flexuosely furrowed throughout (Reeve). 
New Zealand. (Cuming.) 
Carpenter says that this species is from Western America. 
FAMILY—AVICULIDZ. 
Mantle freely open, margins cirrated; no siphons. Palps large. 
Foot small, cylindric, furnished with a byssal grove. Adductor muscles 
very unequal, the posterior much the larger. Shell sub-inequivalve, 
oblique, resting on the smaller or right valve, and attached by a byssus ; 
interior nacreous ; often eared, hinge line straight, cartilage in one or 
several grooves. 
Genus, PINNA—Linneus. 
Mouth with foliaceous lips; anus with a long ligulate valve. Shell 
equivalve, wedge-shaped ; umbones quite anterior ; posterior end trun- 
cated and gaping ; ligament groove linear, elongated. 
P. zealandie, Gray, Dieff: N.Z., ii., p. 259; Reeve, Conch. Ic., f. 
13; Voy. Erebus and Terror Moll., pl. 3, f- 7; P. senticosa, Gould, U.S. 
Ex. Ep., p. 448. Triangular, elongate ; brown ; inside purplish ; valves 
convex, with rather close obsolete longitudinal ribs, armed with close 
short semi-cylindrical hollow spines. 
Height, 4; length, 9°5. 
Auckland to Dunedin. Found also in Australia. 
Genus, AVICULA—Klein. 
Shell oblique inequivalve, fragile, rather smooth ; right valve most 
convex ; a sinus in the left for the passage of the byssus; hinge line 
straight, the extremities produced, the anterior coudiform or beaked ; a 
single cardinal tooth in each valve under the beak. 
I have not seen either of the two following species, and doubt the 
correctness of the locality. 
A. glabra, Gould, U.S. Ex. Ep., p. 442, f- 552. Shell thin, semi- 
elliptical, slightly oblique, surface generally smooth and shining; color 
pale greenish, with opake white radations ; dorsal edge long and straight, 
slightly produced into a queue, from which the posterior edge, after a 
slight inflexion, descends directly at right angles ; back broadly rounded ; 
anterior edge a little oblique ; ear triangular, closely and loosely striated ; 
