MOODIE: MAZON CREEK, ILL., SHALES. 345 
Nothing new can be ascertained of the structure of the 
pectoral girdle. Portions of the scapule, clavicles and inter- 
clavicle are represented, and perhaps the coracoid is indicated 
by a fragment. 
The specimen in hand completes in a very satisfactory 
manner our knowledge of the structure of the pelvis. The 
relations, form and structure of the ilium, ischium and pubis 
are now known quite certainly. The form of the ilium as 
shown in previous restorations was slightly inaccurate. It 
was made a little too long and too curved. It is, instead, 
rather short and nearly straight, with the ends expanded. 
Heretofore nothing was known about the ischium, but the 
present example shows very clearly the form of that element 
on both sides of the vertebral column. Its form is almost 
identical with that of Paleohatteria longicaudata Credner, from 
the Rothliegenden of Saxony. They are apparently approxi- 
mate in the median line, though this character is somewhat 
obscured by the impressions of the caudal vertebre. Its 
relation with the ilium, other than that it was posterior to it, 
is uncertain. All three of the pelvic elements were undoubt- 
edly hung loosely in the flesh of the animal, as in modern 
salamanders, since none of the elements present any marked 
articular surfaces. 
The structure of the sacral vertebra and the. sacral ribs 
still remains to be determined. There seems to have been 
but a single pair of sacral ribs, but the specimen is too obscured 
to shed much light on that point. 
Nothing new is added to our knowledge of the arm. The 
number of phalanges can not be ascertained. Two of the 
digits are preserved entire, and there is nothing in their 
structure to contradict the number given in the restoration 
which is herewith republished. Each hand has a single digit 
of four segments preserved. They undoubtedly represent the 
third digit in each case. 
The elements of the leg and foot are as they are given in 
the restoration. The right foot is preserved almost entire, 
and the digits have the formula 2-2-3-4-3. The distal phalanges 
of the third and fourth digits are lost. There are five digits 
in the foot. 
The fifth anterior dorsal vertebra has a pair of long, curved 
ribs attached intercentrally. The ribs have the same bicipital 
