26 The Philippine Journal of Science 1921 
Such terms as are used should be made clear. References to 
literature should be given whenever available. Descriptions 
should be comparative. Specific diagnoses are often very 
valuable. Systematic discussions should point out which are 
the nearly related species and in what particulars the new 
species differs from these nearly related forms. All this will 
add little to the labor of the systematist who has such details 
at his immediate command, and will add immensely to the use- 
fulness and value of his work, not only to the general student 
but to the systematist so unfortunate as to lack a wide range 
of comparative material and a complete library. 
To return to our original question: Just what is the meaning 
of many of the measurements used? For instance, body length? 
Does it mean from the distal tip of the mandible to the posterior 
tip of the abdomen? If so, does it mean with the head extended 
forward or in any position in which it may chance to be, and 
with the mandibles crossed or extended? Or does it mean the 
length of the thorax and abdomen? These are not idle questions. 
They involve a difference of several millimeters in animals less 
than a centimeter in length. In the Macrotermes soldier, for 
example, the head may assume any position, from that in which 
it forms a line with the long axis of the body to one in which 
it forms a right angle with the body, making a difference of 
3 millimeters or more in total length. Again, head length with- 
out mandibles or, in the nasute soldiers, without rostrum is 
a very indefinite measurement unless carefully defined. 
To avoid the difficulties that I have experienced in using 
descriptions I shall define those terms and measurements which 
I expect to use in my future descriptions. Some changes and 
additions will undoubtedly be necessary as the work develops but 
these will be explained as they arise. 
HEAD SUTURES 
Frontal suture (stem of the Y suture of some authors).—A 
median longitudinal suture dividing the epicranium into two 
equal lateral halves in the region of the vertex. Absent or 
imperfect in most soldiers. 
Transverse suture (arms of Y suture) —Separates the vertex 
from the frons. Absent or imperfect in most soldiers. 
Clypeofrontal suture—Separates frons and clypeus. Absent 
or imperfect in most soldiers. 
