_—_ 
GASTEROPODA. 117 
ble in size, like P. variabilis, Gray. But according to his description, 
it is the lower part of the whorl, instead of the upper, which becomes 
angular and keeled in that species. 
Figure 136, front of the shell; 136, side, with the animal; 136 3, 
shell, natural size. 
Puysa crpposa (Gould). 
Testa obovata, tenuis, glabrata, luteo-cornea: spira acuminata, anfrac- 
tibus quinque rotundatis, ultimo posticé valde gibboso, antice attenuato : 
apertura angusta, subovalis, trientes duas longitudinis adequans ; colu- 
mella sinuata, callo induta. 
Physa gibbosa, Goutn ; Proceed. Boston Soc. Nat. Hist., 11. 214. 
June 1847. Expedition Shells, 42. 
Ayimat large; tentacles short; dark rusty-brown above; fawn- 
coloured beneath; mantle fringe not noticed. 
Suet of moderate size, obovate, rather thin, delicately striated, 
smooth, of a yellowish horn-colour. Spire drawn to a delicate point, 
composed of nearly six well-rounded whorls, the last of which is pecu- 
liarly dilated posteriorly, and forms an obtuse ridge at some distance 
from the suture; anteriorly it is much narrowed. Aperture rather 
narrow, about two-thirds the length of the shell, of an oval form. The 
columella is sharp, and has a small, whitish fold upon it, and the 
penultimate whorl is coated with enamel. Interior brownish. 
Length five-eighths of an inch; diameter three-eighths of an inch. 
Found in fresh-water streams at Paramatta, New South Wales. 
Presented by Mrs. Mitchill. 
The resemblance to P. ancillaria, Say, in the younger specimens, is 
very striking, but the older ones are more like P. tabulata ; the last 
whorl, however, is merely gibbous, and not angular. P. Nove-Hol- 
landie, Gray, is somewhat similar, but is much more elongated, and 
neither angular nor gibbous. 
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