BURRELL. 23 



which the female was present in the chamber when the temperature was taken 

 gives 64.5° F. ; and of four measurements when the parent was not at home, 

 65.5° F. 



The rectal temperatures of seven females captured in the nesting chambers 

 ranged from 86° to 92° F. ; the average being 89.9° F. The blood heat of Ornith- 

 orhynclms would thus appear to be a little more than that measured by Dr. 

 Wardlaw (P.L.S.N.S.W.) for Echidna. 



Plate I. shows five nests of Omitliorhynchus composed of various different 

 materials, details of which will be found in the explanation below. 



Explanation of Plates. 



Plate I. 



Nests of Ornithorhynchus. 



Fig. 1. Nest composed of grass. 

 „ 2. Nest composed of willow-roots. 



3. Nest composed of roots of reed (Artinelo). 



4. Usual type of nest, 90 % gum-leaves and grass. 

 ., 5. Nest composed of stems of Arundo. 



Plate II. 



Eggs and young of Urnitkorkynchus. 

 Fig. 1. Twin eggs, end view. 

 „ 2. Twin young of 65 mm., and the shells of the eggs from which they were 



hatched. 

 „ 3. Side view of the egg* shown in Fig. 1. 



„ 4. Relaxed shells of triplet and twin eggs shown to the right below in Fig. 6. 

 „ 5. Young of 103 mm. 

 „ 6. Above, a dried-up egg; below, shells of single, twin, and triplet eggs from 



which the young have hatched. 

 „ 7. Single and twin egg's from closely adjacent burrows. 

 „ 8. Twin young of 20 mm., just hatched, with shells. 

 „ 9. Twin eggs. 



All figures of natural size, and from photographs in the field. 



