158 Walter Rothschild. 



surface of shaft, and in there being no foramen in groove between 

 3''^ and 4*^' trochleae but a distinct channel above it. 



c) Metapteryx. Differs from Ajdertjx in absence of hindtoe, 

 the elongation of the pedicles of the trochleae and the enormous 

 enlargement of the median trochlea. 



5. Dinornithes. Vomer truncated anteriorly; large post- 

 orbital processes; lachrymal fused with frontals: Mesethmoid 

 produced into paired triangular ventral processes: nasal with 

 slender maxillary process, or a distinct maxillo-nasal bone; sternum 

 with coracoid grooves widely seperated; with metasternal and 

 posterior lateral processes, facets for ribs crowded, shoulder girdle 

 atrophied: wing absent; pelvis very broad; post-acetabular region 

 with the median fossa dividing the innominates only imperfectly 

 ossified: 3 and 4 toed, tibia with an extensor bridge; aftershaft 

 present and as large as main shaft. 



a) Dinornis. Skull broad and much depressed with compara- 

 tively wide, somewhat pointed and deflected beak; breadth at 

 squamosals twice the height at basi-temporal ; hallux present or 

 absent, tibio-tarsus and tarso-metatarsus long and slender; tarso- 

 metatarsus equal to or more öfter exceeding length of femur and 

 exceeding half the length of tibio-tarsus. 



b) Megalopteryx. Differs from Dinornis by the width of skull 

 at squamosals being a little more than twice the height of the 

 basi-temporal; hallux present; femur and tibio-tarsus longer and 

 more slender; tarso-metatarsus shorter than femur and less than 

 half as long as tibio-tarsus. Toes very long, middle toe longer than 

 tarso-metatarsus. 



c) Anomala pteryx. Ditïers from Dinornis by the skull being 

 narrow and vaulted, the beak long, sharp, and slightly deflected; 

 in the breadth of skull at squamosals being 1^/2 times the height 

 at the basi-temporal; in the tibio-tarsus and metatarsus being 

 shorter and stouter; in the meta-tarsus being shorter than the 

 femur and less than V:; the length of tibio-tarsus; and in the femur 

 having more expanded extremities, a longer neck and much larger 

 popliteal depression; hallux present. 



d) Cela. Differs from Dinornis by its convex skull with very 

 large temporal fossae; and by the width of skull at squamosals 

 being 1.7 times the height at the basi-temporal; hallux present 

 or absent. 



e) Emeus. Differs from Dinornis &c. by its very short and 

 wide skull, blunt and slightly deflected beak; it differs from 

 Anomalapteryx, Cela &c. by the much shorter and thicker tibio- 

 tarsus and tarso-metatarsus; the tarso-metatarsus is much shorter 

 than femur and much less than half the length of the tibio-tarsus, 

 and its width at middle of shaft somewhat more than V4 its length. 



f) Pachyornis. Diff'ers from all the other genera at first sight 

 by the very much shorter femur, tibio-tarsus, and tarso-meta- 



