WHEAT: LONG ISI.AXD ACMAEA AND NEW VARIETY OF UROSALPINX. IQ 
line. A lenticular gape appears between the laterals caused by a curling 
of these enlarged bases. This curling gives the laterals an oblique posi- 
tion and causes them to point outward and backward. At the anterior 
end of the radula three or four rows of teeth are badly worn, each 
succeeding row being less abraded than the one before it. The fifth 
row usually is perfect. 
Compared with A. testudinalis the shell is smaller, more con\ex, less 
elongate and less variable in form. Some of the Wading River specimens 
have the base almost round. The average convexity is approximately 
one-third greater than for testudinalis, or as 4 to 3. The index of con- 
\exity, or quotient of the altitude by half the sum of length and 
breadth, was obtained for 40 shells from Long Island. The lowest was 
0.3333, the highest 0.5172, the average 0.41618. The average index for 40 
A. testudinalis, from Maine and the Bay of Fundy (34), Greenland (3), 
British Islands (3), was 0.3128, the highest 0.4285 and the lowest 
0.2040. Of the 40 Long Island shells 29 differed from the average con- 
\-exity by less than ten per cent, and only one by more than twenty per 
cent, while only 22 of the more northern shells were within ten per cent 
of the average and five were more than twenty per cent from it. 
In point of size the northern shell has five or six times the capacity 
of the Long Island shell. Mature shells from the Bay of Fundy 
measured across the base (aperture) are twice as long and almost twice 
as wide as our shell ; but in altitude they are only one-third to one-half 
greater. 
Measurements of Specimens 
FROM Long Island. 
;asurements of Specimens 
FROM Bay of Fundy. 
Alt. 1. & br. of base 
14. 
12. 
II, 
II, 
8, 
5, 
43 X 33 mm. 
39.5 X 29.5 
37 X29 
37 X 29.5 
31 X 23 
22 X16 
g, 
31 X24.5 
33 X26 
36 X28 
Alt. 1 
. & br. of base 
7. 
20 X 16 mm. 
7, 
17 X 13 
7, 
19x15 
8.5, 
19x16 
7-5, 
18 X 16 
4. 
10 X 8 
5-S, 
14 X 12 
6, 
15 X 12.25 
6.5. 
17 X 14.5 
II, 36 X28 7, 17x14 
According to Wilcox, "on the Massachusetts coast a limpet an inch 
long is a giant but at Eastport they not rarely reach a length of 32 mm." 
In Massachusetts all are equal in size and small. In the absence of 
specimens it is impossible to determine whether this small form living 
north of Cape Cod is identical with the Long Lsland form. 
The animal is active, moving freely over the surface of stones and 
shells, feeling the way in advance with its tentacles which are extended 
fully half their length beyond the margin of the shell while moving. 
The foot seems to be equally adapted to moving in all directions. It 
simply pushes outward on the side toward which the animal wishes to 
move, and the other parts follow. The shell generally is elevated 
slightly to permit free use of the tentacles and for the circulation of 
