HuTTON. — Oil Moa-boiies at Kapua. 633 



tibiae, 31 ; femora, 25. Tlie feimu-, relatively to the tibia, is 

 rather saoi'ter than in the two next species, being considerably 

 less than half its length. The diagrams show that D. maxiinus 

 and D. robustus are closely connected : the separation is fairly 

 distinct in the tibias, but it is not possible always to distin- 

 guish the metatarsi and femora of each. Nevertheless, as the 

 difference in size between the typical D. maximus and the 

 smaller form of D. robustus — called by me D. potois — is about 

 one-third, we cannot suppose them to belong to a single 

 species. Mr. Lydekker supposes that this species is the 

 female of D. robustus ; but the distribution of the forms is 

 against the idea. At Glenmark and at Enfield the remains of 

 D. maximus were nearly three times as numerous as those of 

 D. robustus. At Kapua they were about equal, and at Hamil- 

 ton D. maximus was not represented at all. 



The metatarsi and femora show one point of concentration 

 only, but with the tibise there are two, one of which has a 

 length of 31in., the other of 33in. It is possible that these 

 may indicate sexual differences, but more probably they 

 are varietal. The femur varies very much in thickness, 

 and some of those included under D. robustus may belong 

 here. 



The sternum has a breadth just below the costal border of 

 8-5in. to 9in. 



The pelvis has a length of 24in. ; the breadth at the anti- 

 trochanters is 10-5in. ; and the depth of the pre-acetabular 

 part of the ilium is 7'5in. to Sin. 



DiNOBNIS ROBUSTUS. 



IJ. robustus, Owen. 



1). maximus (male), Lydekker. 



D. robustus and D. poteiis, Hutton. 



The number of leg-bones measured was — metatarsi, 39 ; 

 tibi^, 35 ; femora, 40. The femur is about half the length of 

 the tibia. The sternum has a width of Tin. to Sin. just below 

 the costal border. The pelvis has a length of about 21in. ; its 

 width at the antitrochanters is lOin. ; and the depth of the 

 antacetabular portion of the ilium is 6-5in. 



The diagrams of this species show that not only do the 

 tibise concentrate on two points, with lengths of 30in. and 

 27in. respectively, but the femora also show a slight tendency 

 to a double concentration. This may be due either to sexual 

 differences or to the existence of two sub-species. If the first 

 is the true explanation it is probable that the smaller form 

 {patens) is the female, for an individual of this size was 

 found, in 1S61, at Tiger Hill, accompanied by four half-grown 

 chicks. 



