OCR Text |
Show 1903.] OSTEOLOGY OF THE CUCULIFORMES. 283 pliagi, the preilium rises upwards and sweeps inwards in the form of a broad vertical blade with a gently rounded dorsal border, which ultimately meets and fuses with the synsacral crest, terminating in a truncated anterior border cephalad of the synsacral fusion. The ccinalis ilio-lumbalis is wide and spacious. The dorsal plane of the postacetabular ilium is moderately wide, and tapers posteriorly into a blunt, slightly upturned point. Its free outer border is somewhat thickened in Turacus to form a broad lip with sharply defined upper and lower edges ; the inferior of these edges, immediately behind the ilio-ischiadic foramen, is produced into a blunt spine. In Schizorhis the free border of the dorsal plane is sharply defined, so that the blunt point caudad of the ilio-ischiadic foramen is apparent on the dorsal aspect of the pelvis, instead of below this level. The ilio-ischiadic foramen is relatively much smaller in Turacus than in Schizorhis. The ischium expands caudad into an extremely broad plate, especially so in Turacus. The free hinder border of this plate is slightly convex. In Turacus the obturator foramen is cut oft' from the fissure of that name by a descending plate of bone from the ischium. This is not the case in Schizorhis, the foramen and the fissure being-confluent. The pubis is very long, attached for some distance posteriorly to the ventral border of the ischium. The pectineal process is large in both the genera in question. The fovea lumbalis is larger than in the Cuculi, and the fovea ischiadica is distinct from the fovea pudendalis, the latter being cut up into separate compartments by the synsacral ventri-lateral processes. The iliac recess is fairly spacious. viii. T h e P ectoral L im b . The character of the wing is very uniform throughout the group. The humerus only is pneumatic. Most nearly resembling that of the Trogons in its general character, the limb of the Cuculiformes may be distinguished by the greater size of the pectoral crest of the humerus, which forms a linguiform or even triangular plate, and by the prominent collum trochlece, the strongly bowed curve of metacarpal III., and the absence of a backwardly projecting spur on the upper ^ of metacarpal II. In the humerus the coraco-humeral groove (sulcus transversum) is wanting. The crista superior is gently arched, rising from the base of the tuberculum externus and terminating about the upper i of the shaft. In some cases, e. g. Crotophaga, the pectoral crest may be more or less triangular instead of rounded. There is a very small ectepicondylar tubercle. The pneumatic foramen is small; the incisura capitis sharply defined. The humerus of the Musophagi may be distinguished from that of the Cuculi by the fact that in the former the proximal border of the crista superior is long, low, and concave, the distal border short and strongly arched. In the Cuculi there is considerable variation in the relative |