PHILOSOPHICAL TRANSACTIONS. 



Contents op Part III, 1880. 



XXI. A Memoir on the Single and Double Theta-Fuuctions. By A. Cayley, 

 F.R.S., Sadlerian Professor of Pure Mathematics in the University of 

 Cambridge. 



XXII. Eevision of the Atomic Weight of Aluminum. By J. W. Mallet, F.R.S., 

 Professor of Chemistry in the University of Virginia. 



XXIII. Description of some Remains of the Gigantic Land-Lizard (Megalania 



prisca, Owen), from Australia. — Part II. By Professor Owen, C.B., 

 F.R.S., fcc. 



XXIV. On the Ova of the Echidna Systrix. By Professor Owen, C.B., F.R.S., 



&c. 



XXV. On the Determination of the Constants of the Cup Anemometer by Experi- 

 ments with a Whirling Machine. — Part II. By T. R. Robinson, D.D., 

 F.R.S., &c. 



XXVI. On the Dynamo-electric Current, and on Certain Means to Improve its 

 Steadiness. By C. William Siemens, D.C.L., F.R.S. 



Index to Part III. 



Contents oe Part I, 1881. 



On the Structure and Development of the Skull in the Batrachia — Part III. 

 By W. K. Paekee, F.R.S. 



PHILOSOPHICAL TRANSACTIONS. 

 Part III, 1880, price £1 Is. 

 Part I, 1881, price £2 10s. " 



.Extra volume (vol. 168) containing the Reports of the Naturalists attached to the 

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