32 
PATAGONIAN EXPEDITIONS ! PALAEONTOLOGY. 
Lunatia PUEYRRYDONENSIS. 
PL VI, Fig. 12. 
Shell of moderate size, broadly subovate, consisting of about four rap- 
idly increasing convex whorls ; suture impressed, bordered by a narrow, 
flattened shoulder ; aperture subovate, narrow above, broadly rounded 
below ; callus of the inner lip rather narrow and thin, slightly reflected 
over the narrow umbilicus below ; surface marked by numerous distinct, 
crowded lines of growth. 
Height, 33 mm.; greatest breadth, 34 mm.; height of aperture, 28 mm.; 
breadth of same, 18 mm. 
This species is easily distinguished from the preceding by its stouter 
form, shouldered whorls and different sculpture. 
It is possible that these two species may prove to be synonyms of 
European forms, but in the absence of actual specimens for comparison I 
consider it safer to treat them as distinct species, rather than to attempt 
to identify such simple forms by descriptions and figures only, especially 
when the associated faunas are different. 
Locality and position . — Represented by a single specimen from the 
Ammonite (Belgrano) beds at mouth of canon four miles east of Lake 
Pueyrrydon. 
Aporrhais protuberatus sp. nov. 
PI. VI, Figs. 13-15. 
Shell of medium size, rather stout, consisting of six or seven convex 
whorls, of which the last on approaching the aperture becomes carinate 
above the middle and flattened below, the carina extending in a curve to 
the upper extremity of the wing ; aperture rather narrow and elongate ; 
outer lip prolonged upward beyond the preceding whorl and produced in 
a broad, very thick, subquadrate wing, whose outer margin is broadly 
rounded below and extended above in a short blunt process ; inner lip 
with a heavy callus that forms a subspherical protuberance just above the 
anterior canal and extends in a thinner deposit over a large part of the 
spire ; anterior canal short, broad and nearly straight, with a slight notch 
or emargination at the extremity ; posterior canal not distinctly developed, 
but apparently represented by the callus extending up the spire ; surface 
