107 
narrower, with more numerous whorls. No details of ornament. 
accompany the diagnosis. 7. austrina, Watson, from Kerguelen, 
is somewhat broader, the whorls more numerous, not so quad- 
rate, and the two carinating lire not equally disposed. 
Chione permagna, spec. nov. PI. ii., fig. 1. 
Shell triangularly oval, very thick, somewhat heart-shaped, 
very inequilateral, depresse ly convex. Umbones large, de- 
i i h. 
antero-dorsal margin en curved ; ; inner margin of bs 
quite entire.  Lunule broadly elliptic, shallow, its margins. 
Orname solution of crowded re: growth-ridges and lines, 
not raised into lamelle } and on the dorsal-half by rounded 
radial threads with equidistant interstitial furrows, about thirty 
in a width of ten millimetres. 
ro-posterior diameter, 86;  umbo-ventral diam 
sectional diam., 40. A larger and more orbicular example has 
ant.-post. diam., 95 ; umbo-ventral diam., 
This large ponderous shell is probably the largest i in the genus 
hence its specific name; it is distinguishable by its obliquely 
orbicular outline 
ion Hallii, spec. nov. Plate ii., fig. 5. 
Shell oblong-oval, moderately convex, somewhat thick, 
inequilateral ; concentrically grooved, the depressed rounded 
ten millimetres near the ventral margin. Internal margin of 
valves quite entire. 
Antero-posterior diameter, 47; umbo-ventral diam., 38 ; sec- 
tional diam., 21 rg 
ost like C. tris Lamk., but the anterior side is mo 
developed, more Sordat, the post-dorsal — more arched, uM 
the concentric folds narrower an 
e Kergueleni, spec. nov. Ww ii., fig. 9. 
Chion 
Oval-cordate, subventricose. Post-dorsal margin regularly 
convex ; ventral margin slightly curved, a rapidly to the 
m i 
Ornamented with depressed concentrie ridges, separat ted by 
narrow deep sulci ; about eight ridges in a width of ten milli- 
metres at the front (but the various examples show considerable 
variation in the number of.the growth-ridges) ; faintly radiately 
and densely striated at least on the sub-surface shell-layer. 
