. 
No. 384.] SHELL OF HELIX NEMORALIS. 915 
are fused into one, they are enclosed in a parenthesis, as 123(45). 
In my lists a distinction is made in the order of fusion, thus 
[(t2)(3(45))] indicates that bands 4and 5 are first fused, then band 
3 unites with this fused band (45), bands 1 and 2 are also fused, 
and finally all the bands are united into one. An v is used to 
denote a band which cannot be referred to any of the usual 
five bands ; such bands are generally rudimentary, but in a few 
instances they are equally strong with the other bands, and then 
designated by X. A split band is marked by doubling the num- 
ber if both bands are strong, as 122345, and by adding a small 
number if one of the bands is weak, as 122345. In one case 
only a rudimentary band passes from one band to another, 
fusing first with one and then with the other; this is var. 
libellula 1(2'%,3)(45). 
TABLE I.— FREQUENCY OF ALL VARIETIES OCCURRING MORE 
THAN Five TIMES. 
(In percentage.) 
FORMULA. SERIES SERIES SERIES FORMULA. SERIES SERIES SERIES 
A. B. SA A. B. C 
12345 40. 41I 31.6 | 120(45) 0.4 0.5 0.3 
(12) 345 0.7 0.6 7 | 12345 0.9 0.6 0.4 
123 (45) 12.3 10.5 17-2 | 10345 I.I L.I 2.2 
(12) 3 (45) 4 4-4 5-2 | 12345 0.6 0.5 2.9 
(123) (45) 0.4 0.6 1.9 
I (2345) o o 0.5 | 00300 8.2 8.8 0.2 
(12345) 0.4 O.I 0.8 | 0030s 0.9 I OI 
[123 (45)] o o. 1.3 | 00340 ps op ò 
[(12) 3 (45)] o. 0.2 0.6 
00000 4. 2.6 5- 
12345 1.2 0.9 3 
123 (45) 0.3 0.6 1.5 | 122345 0.6 o4 o2 
10345 6. 6.2 2.5 | 123245 1.1 1.3 0.9 
12345 3.6 4. 3.7 | 123a (45) 0.4 0.4 0.7 
123 (45) o. 0.2 0.5 | (12) 3x (45) 0.3 0.2 0.5 
(123)2(45) 0.2 o. 0.5 
12045 1.4 2. 1.2 
Originally each variety was designated by a distinct name. 
Certain of these names are now used to designate the color of 
the type, and the banding is expressed by the formula. Thus 
petiveria was fawn and bandless, but the name is now applied 
