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13 
fragility and acquired bird-like powers of escape left the fewest 
remains. 
The connecting or intermediate forms between the Dinosauria 
and the true birds were very few. One, the most interesting and 
important, the Archzoptery of the Solenhofen fresh-water lime- 
stone was a feathered flying reptile with sclerotic rings to its 
eyes, un-anchylosed pelvic arch, three clawed digits on each fore 
limb, one of which at least was free and functional although the 
other two seem to have been enveloped in a stiff patagium and 
supported a system of primary and secondary quills of the usual 
flying-bird type. It unquestionably had a horny beak and teeth 
of the usual simply conical reptilian pattern. Its tail was tran- 
sitional, each of its sixteen joints carrying a pair of true feathers 
of which it was difficult to see the use in such a position. 
Although the first Bird to our knowledge it was evidently 
the descendant of a long series of highly specialised forms of which 
at present we know nothing. [For instance, the feathers of the 
existing Apteryx were of a more archaic type than those of this 
fossil from the Jurassic. We had much left to learn. 
Between the Archzorpteryx and the fairly numerous bird 
remains of early Tertiary deposits, most of which can be assigned 
to existing families and even genera, stand Professor Marsh’s 
discoveries in the Kansas Chalk, Hesperornis a Struthious, 
or Ostrich-like swimming bird with degraded wings, reptilian, 
tail, and keel-less breast-bone, and the small and graceful 
Ichthyornis of gull-like outline, bearing wings of the modern and 
familiar type associated with a deeply-keeled sternum and fan- 
shaped tail. Both species had teeth, and the latter’s cervical 
vertebrze were bi-concave and fish-like in type, the last 
occurrence in the pedigree of the bird of a structural peculiarity 
of immense antiquity and since superseded, even amongst most 
reptiles. 
The lecturer then addressed himself to the skeletal frame- 
work of the bird, and with the assistance of specimens and 
diagrams pointed out homologous structures in the preceding 
saurians and amphibians, traced the beginnings and history of 
the Pelvis, the first indications of the sternum superseding the 
at one-time all-important Coracoid bones in the circuit of the 
pectoral girdle. 
The steps by which the normal reptilian leg with tibia, fibula 
and five toes was reduced to the leg of the modern bird were pur- 
sued in considerable detail in a series of diagrams, in which 
homologous structures superficially most unlike were connected, 
