19 
HALIPLID^E. 
G. E. Crotch. — Ee vision of the Dytiscidse of the United States. 
<Trans. Amer. Entom. Soc., Yol. IV, 1872-’73; Haliplides, pp. 
383-385. 
DYTISCID^E. 
G. E. Crotch. — [Work just cited; Dytiscides, pp. 385-424.] 
David Sharp. — On aquatic carnivorous Coleoptera or Dytiscidse. 
CTrans. Eoyal Dublin Soc., 1882, Ser. 2, Yol. II, pp. 179-1003, 
plates. 
A monograph of the Dy tiscidae of the whole world. 
GYRINID.E. 
John L. Le Conte. — The Gyrinidse of America, north of Mexico. 
<Proc. Ac. Nat, Sc. Phil., 1868, pp. 365-373. 
M. Eegimbart. — Essai monographique de la famille des Gyrinides. 
<Ann. Soc. Ent. de France, 1882- , 83, with eight plates. 
Treats of the Gyrinidae of the whole globe. 
HYDROPHILIDJE. 
John L. Le Conte. — Synopsis of the Hydrophilidse of the United 
States. <Proc. Acad. Sc. Phil., Yol. YII, 1855, pp. 356-375. 
George H. Horn. — Eevision of the genera and species of the tribe 
drobiini. <Proc. Amer. Philos. Soc., 1873, pp. 118-137. 
SILPHID^E. 
John L. Le Conte. — Synopsis of the Silphales of America, north of 
Mexico. <Proc. Ac. Nat. Sc. Phila., Yol. VI, 1853, pp. 274-287. 
George H. Horn. — Synopsis of the Silphidse of the United States, 
with reference to the genera of other countries. <Trans. Amer. 
Entom. Soc., Yol. VIII, 1880, pp. 219-322, PI. V-VII. 
SCYDMJENIDiE. 
John L. Le Conte. — Synopsis of the Scydmaenidae of the United States. 
<Proc. Ac. Nat. Sc. Phila., Vol. VI, 1854, pp. 149-157. 
PSELAPHIDAE. 
John L. Le Conte. — On the Pselaphidse of the United States. <Bos- 
ton Journ. Nat. Hist., Yol. YI, 1850, pp. 64- 110. 
Emil Brendel. — Synopsis of the genera and species of the family Pse- 
laphidse. <Proc. Ent. Soc. Phil., Yol. YI, 1866-7, pp. 31-38. 
