WILLISTON: RESTORATION OF ORNITHOSTOMA (PTERANODON). St 
Pialangesy third digit length or secontiny sci yy) ae mm. 
Soy 5 5 4 
Phalanges, ‘“ Ebi eaneed aGdohmameln bk qal sie uve MMi ir csariAMln akua, Sy, 
o oS Y 
Phalanges, ‘‘ Gh sali cha vedtel buvopeman koh ith lao Marana tes A aaMNe Aas ie 
toy ’ t 
Phalanges, fourth digit, length of proximal.......... 40 
Phalanges, ‘‘ Ho HEN STM Ol SRCO Metin ace ca ht ule 
Phalanges,  ‘ SS SOLE IVerttty, On wot ie Chaikin sen iiaAMil vite gene ini 
34 § 3 
Phalanges, ‘: eC Nemeth oop Out tien at 'alye aewoee taunt es 
Phalanges, eee shat snl binouasanGl aaa ee aNeH ty MeN I Ry oh sabi" 
Summary of Charactzrs, Ornith7stoma. 
Head much clongated, the jaws slender, pointed and wholly 
wanting in teeth. External nares and ante-orbital vacuities united; 
supratemporal fossa of large size; occipital crest elongated. Neck 
elongated, non-costiferous, with exapophysial articulations, and 
rudimentary spines. ‘Three anterior dorsal vertebra co-ossified and 
bearing a supraneural plate for articulation with scapula. Poster- 
ior dorsal vertebrae decreasing in size, procoelous, the trensverse 
processes situated high up. Sacrum composed of six or seven ver- 
tebra, the anterior ones with long transverse processes, the poster- 
ior three sessile. Tail short, small, the vertebrae without transverse 
precesses and amphiplatyan. Anterior ribs strong, double headed, 
those of the co-ossified vertebre anchyloned to vertebra. Pos- 
terior ribs weak, single headed; adbominal ribs present. Coracoid 
and scapula united, the latter articulating with supra-neural facet, 
the latter with the sternum; a scapular foramen present. Sternum 
pentagonal in outline, with stout anterior projection; the sides with 
four costal articulations. Ilium with an elongated anterior projec- 
tion; pubés free, band-like, co-ossified, with anterior articular 
projection, the bone attached to tuberosities on the anterior border 
of the ischia. Ischia broad, uniting in a symphysis posteriorly, 
with ‘‘thyroid” foramen, below acetabulum. Bones of the forearm 
longer than the humerus, and shorter than wing metacarpal.  Car- 
pus composed of three bones, in two rows; median phalanges of 
second, third and fourth fingers short; four phalanges in the pa- 
tagium, the terminal one curved or straight. Femur curved, 
trochanter small; tibia longer than the femur, with trochlear artic- 
ulation below; fibula wholly wanting; tarsus with two bones only, 
ina single row; four functional toes, elongate, slender, the fifth 
consisting of a rudimentary metatarsal; middle phalanges of third 
and fourth toes very short; first and second without true claws. 
