INTRODUCTION. 
Twenty-two families of beetles are dealt with in this Volume: the Silphide, Cory- 
lophide, Trichopterygide, Spheeriide, and Scaphidiide by the Rev. A. Matthews, the 
Histeride by Mr. Lewis, and the remainder by Dr. Sharp. ‘The Heteroceride, Parnide, 
Georisside, and Cyathoceride were placed with the other aquatic and subaquatic beetles 
in Vol. I. part 2, and the Erotylide and Endomychide in Vol. VIL., of the Coleoptera, 
these families being sometimes included amongst those here enumerated. We have 
delayed closing the present volume in the hope of being able to add descriptions of 
the various ‘‘Genera incerte sedis” still remaining in our collection, but this has 
proved to be impracticable. Dr. Sharp, however, has described the Rhipidandri, Lec. 
(=Eutomides, Lacord.), a group that has been variously referred by different authors 
to the Tenebrionide, Scolytide, Cioide, and Trogide. A certain amount of supple- 
mentary material has come to hand, and the numerous missing Hapalips from Guatemala 
and Panama (to which attention was called in Vol. VII. p. 250) have now been found, 
but too late to be included here. 
For the families Pselaphide to Byrrhide, inclusive, and the Rhipidandri, 1532 
species are altogether enumerated, of which 996 are described as new, with 83 new 
genera. The number for each family is as follows:—Pselaphide, 100 (69 new); 
Scydmenide, 67 (49 new); Silphide, 33 (20 new); Corylophide, 29 (25 new); 
Trichopterygide, 54; Spheriide, 1 (new); Scaphidiide, 35 (27 new); Histeride, 247 
(86 new); Phalacride, 49 (41 new); Nitidulide, 286 (196 new); Trogositide, 107 
(65 new) ; Synteliidee, 2; Adimeride (new family), 3 (all new) ; Colydiide, 96 (75 new) ; 
Rhysodide, 2 (1 new); Cucujide, 140 (98 new); Monotomide, 31 (29 new); Crypto- 
phagide, 103 (94 new); Lathridiide, 23 (17 new); Mycetophagide, 9 (6 new) ; 
Dermestide, 71 (54 new) ; Byrrhide, 37 (84 new); and Rhipidandri, 3 (2 new). 
During the progress of the work, 97 species (27 of which were obtained amongst 
the refuse of Mexican tobacco stored in Paris) have been described by various authors 
