30 Osteological Studies of the Subfamily Ardeincz. 
19. There are 44 vertebrae and a pygostyle in the vertebral 
column of the Ardeincz. In all, the dorsal series are free ; in all, 
the 24th to the 37th inclusive are anchylosed with the pelvic bones; 
in all there are 7 caudals. In Ardea the 18th and 19th vertebrae 
bear free ribs, and all seven caudal vertebrae are free. In Nycti- 
corax violaceus the 17th, 18th and 19th vertebrae bear free ribs, and 
the anterior caudal vertebrae anchyloses with the sacrum. The 
pygostyle is comparatively small. The epipleural appendages of 
the ribs are small and free. 
20. Sternum of good size ; its manubrium prominently devel¬ 
oped ; broadly 2-notched ; four articular facets on either side for 
costal ribs ; carina rather deep, its lower border convex and nearly 
the arc of a circle ; dorsal aspect very concave ; coracoidal grooves 
decussate ; costal processes broad ; one large pneumatic foramen 
in the median line above, just ovct anterior border. 
21. Coracoid and scapula non-pneumatic; coracoid very broad 
below, antero-posteriorly ; compressed from side to side above ; 
scapular process small ; slight differences in the two bones, at 
their sternal ends, due to their crossing each other. Scapula 
broad anteriorly, much compressed from above, downwards ; apex 
rounded ; blade rather long, not truncate, but tapers gradually to 
the end. Furcula non-pneumatic ; upper half of each limb con¬ 
vex anteriorly, the reverse below ; when articulated with coracoid, 
nearly reaches the scapula at the inner anterior angle of its head; 
hypocleidium has a superior and an inferior process. 
22. Pelvis is rather massive ; pre- and postace tabular surfaces 
about equal; ischic foramen large; obturator foramen opens 
largely into obturator space ; ilio-neural grooves sealed over ante¬ 
riorly ; one pair of free ribs articulate with the pelvis. 
23. The humerus is the only pneumatic bone of the pectoral 
limb, the periphery of the orifice being in the general surface ; 
remainder of limb well proportioned. Bones of pelvic extremity 
long and straight-shafted, except the fibula, which is short. In 
Ardea fibula short and free below. In Nycticorax violaceus fibula 
long and anchylosed with tibio-tarsus below. 
24. Tendinal osseous bridge at lower end of tibio-tarsus exists 
and is thrown nearly square across the groove. 
25. The hypo-tarsus of the tarso-metatarsus 3-crested, grad¬ 
uated in size, the outer being the smaller ; the tendinal grooves 
pass between them. 
