50 
MAURICE G. MEHL 
anterior end of each gives a choice between a large and small 
parasphenoid. It will be found that with the use of the small 
vacuity and small parasphenoid, the sutures between the pala- 
tines, pterygoids, and vomers will have to be slightly modified. 
A false palate may be indicated by adding a line drawn across 
the bones of the palate along points at which the fold takes 
place. Arrows pointing from this line to the median line of the 
skull indicate the fold somewhat more effectively. 
Teeth on the various elements may be designated by circles 
or crosses. The various types, thecodont, acrodont, etc., may 
be designated by special symbols agreed upon. 
The posterior view gives a choice between a single and double 
occipital condyle. When the single condyle is utilized the out- 
line remains unchanged. The suture between the tabular and 
the. paroccipital is left incomplete so that it may be continued 
toward the median line of the skull in any direction so as to 
maintain the desired relations between the supraoccipital and 
the laterally adjacent bones. 
An index sheet, plate VIII, furnishes the names in common use 
for the various bones of the skull. Most of the openings are 
indicated in a like manner. To eliminate confusion, openings 
are indicated by a curved line beneath the abbreviation for the 
name. Unpaired bones are underscored with a straight line. 
In filling out a chart the same abbreviations should be used as 
are given in the index sheet, and the openings and unpaired bones 
should be designated in the same manner. 
THE LIMBS 
The guide chart for the limbs, plate X, furnishes outlines for 
both the front and the hind legs. Names of the various elements 
should be added by the student. All of the elements in the 
primitive leg are represented by conventional designs save in 
the case of the mesopodials. Here there is so much doubt as to 
the primitive arrangement and number, and such a variation 
among known forms, that only the lines to designate the three 
rows are given. Between these, vertical lines may be drawn to 
