PREFACE. XXV11 



of the type rocks was deposited in the Museum d'Histoire Naturelle, at Paris, in the 

 possession of Prof. A. Lacroix, consisting of the following: 



Nos. 1, 5, 68, 119, 129, 140, 158, 187, 200, 270, 443, 449, 450, 470, 473, 488, 514, 518, 

 520, 526, 528, 533, 536, 543, 544, 549, 550, 554, 555, 557, 563, 571, 598, 603, 607, 620, 624, 

 625, 627, 637, 638, 682, 695, 699, 744, 746, 754, 797, 799, 801, 805, 828, 835, 854, 864, 865, 

 866,867, 868, 869, 871, 872, 873, 874. 877, 879, 882, 883, 890, 892, 903, 911. 916, 921,923, 

 936, 947, 950, 954, 958, 960, 963, 979, 983, 989, 991, 1044, 1049, 1050, 1059, 1061, 1062, 1068, 

 1073, 1074, 1094, 1098, 1100, 1109, 1128, 1129, 1136, 1137, 1277, 1278, 1283, 1312, 1318, 

 1340, 1409, 1428, 1436, 1518, 1797, 1838, 1843, 66G. 



An analytical key of the petrographical descriptions of this volume will be 

 found after the Table of Contents. 



NOTE. It is recognized that the criterion by which diopside has been determined (cleavage 010) is not 

 alone reliable ; but usually diopside has been identified further by its elongated form, its light color, and its 

 association with acid and alkali minerals, and by its occurrence in secondary rocks. 



The reader will please note the following corrigenda: 



On p. 169, line 12, for magnetite read magnesite. 



On p. 180, line 10, for LABRADOBITE read LABBADORYTK. 



On p. 209, line 24, add the words: See Nos. 132A and 667. 



On p. 309, line 25, add the words: Plate V, figure 9. 



On p. 313, line 18, add the words: Plate VI. 



On p. 344, line 14, add the words: See No. 884. 



On p. 350, line 24, after crystals, add: and coarser ones of tourmaline. 



On p. 456, line 3 from the bottom, add: Plate II, figure 1. 



On p. 464, read LABRADORYTE and THOMSONITE. 



On p. 473, line 6 from the bottom, add: Plate II, figure 2. 



On p. 559, line 10, erase 1842. 



On p. 644, line 18, for band read bond. 



On p. 660, first line, for same read some. 



On p. 735. line 25. add the words: Plate V, figure 7. 



On p. 785, line 3, add the words: See note, p. 161, Twenty-first Annual Report. 



On p. 844, line 18, add the words: Plate III, figure 5. 



N. H. W. 



