402 PROCEEDINGS OF THE NATIONAL MUSEUM voL. 113 
designated the precondylic spur as the anterior spur, the postcondylic 
spur as the medial, and the caudal spur as the posterior. Ribaut 
indicated the prefemur withthe upper-case letter P, the leg’s dorsal 
surface with a lower-case d, and the anterior, medial, and posterior 
spurs with the lower-case letters a, m, and p, respectively. In this 
fashion he was able to identify every spur of the animal’s leg. Thus, 
daP refers to the anterior dorsal spur of the prefemur; dmP refers 
to the medial dorsal spur of the same article. 
In my publications I have employed the qualitative approach of 
Ribaut but have slightly modified its terminology for greater clarity 
and utility, and to bridge the purely linguistic discrepancy between 
French and the more acceptable Greco-Latin root-words that are 
universally understood and employed by zoologists. My revised 
formularization involves three upper-case letters. The first (from 
the left) refers to the surface of the leg (dorsal or ventral), because 
when one examines a specimen, dorsal or ventral orientation is the 
first consideration taken into account. The second letter refers to 
the leg article: C, coxa; Tr, trochanter; P, prefemur; F, femur; Ti, 
tibia. Note that a second and lower-case letter conveniently dis- 
tinguishes between trochanter and tibia. ‘The third letter refers to 
the particular spur: A, anterior; M, medial; P, posterior. Thus, 
DPA refers to the anterior spur dorsally on the prefemur. In fig. 1 
the several spurs are labelled. 
This system lends itself readily to a variety of useful presentational 
schemes. The format presented here is probably the most useful 
in that it conveys a maximum of information at a glance and in addi- 
tion can be readily adapted to derivative schemes of a more specialized 
nature. The format illustrated in this paper is a slight modification 
of that published by Broelemann in 1930. The reader is referred to 
table 1. 
The numbers in the first column refer to the 15 pairs of legs. Ceol- 
umns are provided for the descriptive codes representing the coxa, 
trochanter, prefemur, femur, and tibia under the headings ‘‘Dorsal” 
and “Ventral.”” Thus, each intersection of a vertical column with a 
horizontal column represents a particular leg article of a particular 
leg, and the letters in each such intersection show which spurs there- 
upon are present and absent. For example (see table 1 for Lithobius 
forficatus), beneath “Dorsal” and “P” and opposite 10 we find the 
letters AMP. Beneath “Ventral” and ‘Tr’ and opposite 15 we find 
only the letter M. Finally, note that an italic letter means that that 
spur is variable in that position, that is, it may be either present or 
absent. 
Quantitative formulae are readily derived from such a format. 
Merely by adding the letters in each square for a given leg we may 
