SPECIAL DIRECTIONS TO BINDER.

Plates XVII. and XVIII. should be so placed that when bothare unfolded they will be side by side for comparison.

Plates XXI. and XXII. should lie the same way, the top of eachtowards the left, so as to admit of being studied simultaneously.

ERRATA.

Plate VIII. fig. 30. - For “ inwards,” read “ outwards.”

fig. 31.—For “ outwards,” read “ inwards.”

Plate X. fig. 39.—The arrow near arc N'M' .should be below the I,not above as shown, and the arrow near the arc NM shouldbe above the I, instead of below.

Plate XIII. fig. 55.—M,, near top, should be M 2 .

For fig. 53a read 56 a.

Plate XV. fig. 77.—The left-hand 0 should be O'.

At p. 28, line 9 from bottom of page, for “ more ” read “ less.”

„ p. 208, „ 3 „ „ „ for “ that her, read “ than

that her.”

„ p. 349, „

3 ,, top

for “ dusty,” read “ dusky.’