[42 FIELD COLUMBIAN MuSEUM—GEOLOGY, VOL. II. 
marked ridge, also for muscular attachment, traversing the anterior face 
obliquely, and terminating near the lower, outer angle of the process. 
Firbringer says of these processes in the pterosaurs: ‘“ Proc. lateralis und 
Proc. medialis, namentlich aber der erstere sind sehr kraftig entwickelt 
und prominieren insbesondere proximal so stark, dass das zwischen 
ihnen befindliche Caputhumeri sogar theilweise gegen sich zurucktreten 
kann; dagegen ist— sehr im Unterschiede zu den meisten Sauropsiden, 
namentlich aber den Theromorphen und Dinosauriern — der Proc. later- 
alis wenig in die Lange entwickelt, indem er gewO6hnlich nur das proximal 
yy bis % des Humerus einnimmt. Diese Konfigurationen lassen darauf 
schliessen, dass die Mm. supracoracoideus (supracoracoscapularis, scapulo- 
humeralis posterior und subcoracoscapularis) eine relativ hohe Entfaltung 
besassen, der M. pectoralis dagegen keine so abnorme Starke darbot, 
wie es von vornherein von einem fliegenden Thiere erwartet werden 
konnte, und der M. deltoides nur mittelstark entwickelt war.”* 
The shaft below the lateral process is of nearly uniform width. A little 
above the middle of each bone, on the inner or ventrolateral side, starting 
from precisely the same place, and lying transversely, there is a slender 
bone, less than a millimeter in width, and about twelve millimeters in 
length, preserved. I do not know what it is, nor whether it really 
belongs in this position, though the similarity of the bone on the two 
sides suggests that it does. It may be an ossified tendon. . . Because 
of the position in which both humeri are lying, the distal extremity 
has been transversely compressed, effacing the articular surfaces to a great 
extent. There seems to be a small depression on the inner epicondyle. 
MEASUREMENTS OF HUMERUS. mm. 
Length 22-2 20s os 2 ee ee PER Sete eg se See ee oe a 87 
Least ‘width of shaft: 2-2-2922 2--es-0 2 se 55 2 5 
Heastwidthotlaterals processi-- eee see ae oon. otnoh oer 17 
Width of latéral procéss distally .2-s.-2 2. s.-..-.-.- 3-2 ar 25 
Width of humerus through lateral: procéss--. -...--...+..._ 7a 42 
Width. of median. process:22-2<. =S-7 .J__- - = -¢- =. 3-25 -_- 
Ulna. Pl. XLII, Fig. 2. The bones of the left forearmplieineariaa 
position, and in contact with the distal end of the humerus; those of the 
right side have been slightly separated, the radius detached and removed 
proximally. The left ulna is lying nearly upon its outer side, partly over- 
lapping the radius; that of the right forearm has been compressed dorso- 
ventrally. The bone is slightly expanded at the extremities. There are 
two, nearly confluent, articular surfaces at the proximal end, the smaller, 
nearly circular one, on the inner side, nearly confluent with the large, less 
*Jenas. Zeitschrift, 1900, p. 363. 
