DIRECTIONS TO THE BINDER FOR PLACING THE PLATES IN THIS VOLUME. 



Plate I. f Illustrating Dr JohB Denis Macdonald's Paper on the Order and Classi- 



II. I fication of Heteropoda, . . . .To face page 20 



-rjy I Illustrating Mr Wm. Turner's Paper on the Structure of the Ghondracan- 



■ ( thus LojoMi, with Observations on its Larval Form, . . .76 



-r^ J Illustrating Mr Wm. Turner's Paper on the Structure oi Lerneopoda Dal- 



' \ manni, with Observations on its Larval Form, . . .88 



^ J Illustrating Mr Edward Sang's Paper on the Deflection of the Plummet 

 * I due to Solar and Lunar Attraction, . . . . .94 



-yj f Illustrating Sir David Brewster's Paper on the Existence of Acari between 



■ \ the Laminae of Mica in Optical Contact, . . . .96 



-yjT f Illustrating Sir David Brewster's Paper on Certain Vegetable and Mineral 



■ \ Formations in Calareous Spar, ..... 98 



-rry-rj J Illustratiug Profcssor William Thomson's Paper on the Secular Cooling 

 ^^^^•\ of the Earth, ........ 170 



/ Illustrating Dr John Denis Macdonald's Paper on the Representative 



Relationships of the Fixed and Free Tunicata, regarded as two Sub- 



-ry ( Classes of equivalent value (figs. 1, 2) ; on the Zoological Character 



■ I of the living Clio caudata, as compared with those of Clio horealis 

 I given in Systematic Works (fig. 3) ; and Notes on the Anatomy of the 



^ Genus Firola (fig. 4), , 192 



X. J Illustrating Sir David Brewster's Paper on the Structure and Optical 

 XL \ Phenomena of Ancient Decomposed Glass, .... 204 



YjT J Illustrating Sir David Brewster's Observations on the Polarization of the 



' ( Atmosphere, made in St Andrews, . . . . . 240 



r Illustrating Professor Allman's Paper on a Pre-brachial Stage in the 



XIII. < Development of Comatula, and its importance in relation to certain 



( Aberrant Forms of Extinct Crinoids, ..... 252 



XIV. \ 



XV 



YYl \ Lliistrating Dr R. E. Scoresby- Jackson's Paper on the Influence of Weather 



■ j upon Disease and Mortality, ...... 348 



XVIII. J 



yry f Illustratiug Sir David Brewster's Description of the Lithoscope, an Instru- 



■ \ ment for Distinguishing Precious Stones and other Bodies, . . 424 



XX. Illustrating Professor Kelland's Paper on Superposition, . . . 474 



XXL r Illustrating the Rev. Robert Boog Watson's Paper on the Great Drift 

 XXII. 1 Beds with Shells in the South of Arran, . . . .546 



XXIII. ' 



XXIV 

 ^Yv* Illiistrating Professor Smith's Paper on some points in the Metrology of 



-£^j- the Great Pyramid, ....... 706 



XXVII. 



XXVIII. f Illustrating Dr J. B. Pettigrew's Paper on the Structure and Action of 

 XXIX. \ the Auriculo- Ventricular Valve, . . . . .806 



VOL. XXIII. PART III. C 



