640 Transactions. — Geology. 



The sternum has distinct, but round and shallow, cora- 

 coidal pits, very different from those of A. parva. The width 

 below the costal border is 3-7in., and the length of the body is 

 3'5in. 



The pelvis has a length of 15-7in., and its width at the 

 antitrochanters is 1-bm. ; the depth of the pre-acetabular 

 portion of the ilium is 3 "Tin. It is relatively broader than the 

 pelvis of A. jMrva, but resembles it in other respects. From 

 the pelvis of M. didinus it can be distinguished by the com- 

 pressed centra of the pre-sacral vertebrae, and by the greater 

 length of the mass of sacral vertebrae (numbers 35-37), which 

 have no transverse processes. 



As A. fortis is a species not mixed, either at Kapua or at 

 Glenmark, with any other of the same genus, it will perhaps 

 give us some idea of the amount of variation in size in the 

 different species of moas. I find that the metatarsus varies 

 about 1 in length and i in mid- width. The tibia varies i in 

 length and Jj in mid- width. The femur varies i in length 

 and jij in mid-width. In the metatarsus both the distal and 

 the proximal width vary about i ; but in the tibia and in the 

 femur the distal width is the most constant element, the 

 variation being only J^ and Jy respectively. It thus appears 

 that the metatarsus is the most variable bone. 



Genus PACHYOENIS. 



In the femicr the head is rather short, the neck thick and 

 but slightly constricted. The internal troclianterial surface is 

 flat, or slightly concave. The transverse section of the shaft 

 is usually oval, but it is variable. The linea aspera is broken 

 and not well marked. The popliteal depression is short and 

 deep ; the two tuberosities are usually separated, and the 

 inner one placed on the inner margin of the popliteal depres- 

 sion. The distal extremity is much expanded ; the inter- 

 condylar fossa nearly as deep on the outer as on the inner 

 side. From the femur of Eurijapteryx it may be distinguished 

 by the shorter and thicker head, and by the internal trochan- 

 terial surface being flatter. 



The length of the tibia is between 7f and 11 times that of 

 the width of the shaft in the middle. The shaft is usually 

 straight, but sometimes it is considerably curved inward ; its 

 antero-outer surface is usually convex (flat in P. imvianis). 

 The distal extremity is much expanded inward, and the distal 

 width is almost always more than 3"3in. The extensor bridge 

 and its tubercle are directed at the outer condyle. 



The length of the metatarsus is from 3 to 4^ times that of 

 its mid-width, which is always greater than that of the tibia or 

 femur. The proximal articular surface has the inner margin 



