156 Transactions.—Zoology. 
anteriorly, Perhaps this and the next species should form a distinct genus; 
certainly they do not belong to Physa. I would propose that Adams’ sub- 
genus Ameria be retained for them. 
Buus varzsiuis, Gray (Physa). Animal and radula like B. gibbosa, 
but with only 112 transverse rows of teeth. Teeth 18-1-18, of which seven 
or eight are laterals. Generally the teeth are similar to those of B. gibbosa, 
but the base of the central tooth is as broad as long at its posterior margin, 
and the reflected portion is simply convex anteriorly ; the teeth are larger 
and coarser, and the outer marginals are not so long. (Pl. IV., fig. p.) 
This description is taken from the common species found in the neigh- 
bourhood of Christchurch. It is very variable in shape, the whorls being 
either rounded or slightly flattened behind; the body whorl usually bears 
indications of a keel, formed by a single row of fine short hairs, but some- 
times this is absent. The spire is more produced than in B. gibbosa, and 
the whorls are not so much flattened behind as in P. masta. Whorls 4; 
columella plait distinct. 
Probably the other species of Physa described from New Zealand will all 
be found to belong to the same genus. 
Latta neritow:s. I have to thank Mr. T, F. Cheeseman for numerous 
specimens, preserved in spirit, collected by him in Lake Pupuke, near Auck- 
land. I have never seen the genus in the South Island. 
Animal, The eyes are at the outer bases of the tentacles, which, in 
spirit specimens, are short, incurved, and transversely ringed. (Pl. IV., 
fig. v.) 
Dentition. There is no jaw. The radula is ‘08 inch in length, and ‘04 
inch in breadth, the sides nearly parallel. There are 80 transverse rows of 
teeth, which form an angle of abont 115°, salient anteriorly. (Pl. IV., 
fig. p.) The teeth are 27-1-27. The central tooth is small, the reflected 
portion half the length of the base, and bicuspid, but apparently without 
any cutting points. The laterals are all nearly alike, and increase in size 
outwards to about the sixteenth, and then diminish. The base is con- 
stricted in the middle, and the outer side has two teeth near the posterior 
end. The reflected part is oblique to the base, single cusped, with @ 
rounded cutting point. (Pl. IV. fig. z.) 
The position of the eyes, outside the tentacles, would appear to take 
Latia out of the Limneide, and the absence of a jaw, as well as the arrange 
ment of teeth on the radula, are other characters by which itis distinguished. 
It may form the family Latiide. 
AMPHIBOLA AVELLANA. In a paper on the anatomy of this species, in the 
“Ann. Nat. Hist.” for 1879, I briefly described the dentition, but the des- 
cription is not sufficiently accurate, and I have inadvertently stated that 
