DYTISCIDJS. 
Ins. 35 
described in this work. The Dytiscidce are divided into two main 
groups, Dytisci Fragmentati and Dytisci Complicati, according to whether 
the metathoracic episternum reaches the middle coxal cavity or not ; but 
it would be difficult to give a coherent account of the classification 
adopted, owing to isolated genera being frequently treated as equivalent 
to named tribes and groups. No references, or even authors’ names, are 
quoted for genera. 
The following known species are figured :—Pelobius australasice, 
Clark, fig. 10G, Noterus clavicornis , De Geer, fig. Ill, Colpius inflatus, 
Lee., fig. 112, Canthydrus nigrinus, Aub6, fig. 114, Ilydrocanthus 
grandis , Lap., fig. 115, Vatellus tarsatus, Lap., fig. 117, pi. ix., 
Amphizoci insolens, Lee., pi. x. fig. 121, Hyphydrus japonicus, Sharp, 
figs. 137 & 138, australis , Clark, fig. 139, pi. xi., Ccelambus acaroides 
and nubilus , Lee., pi. xii. figs. 145 & 147, Ilydroporus undulatus , Say, 
lapponum , Gyll., nigriceps, Schaum, and addendus, Crotch, figs. 157-160, 
Celina aculeata , Aube, fig. 161, Agabus cordatus, Lee., fig. 165, pi. xiii. 
cephaloles , Reiche, branneus , Fab., gagates, Aube, disintegrate , Crotch, 
bifarius , Kirby, conspicuus , Sharp, fuscipennis and serricornis , Payk., 
pi. xiv. figs. 166-173, Platambus pictipennis , Sharp, fig. 180, Ilybius 
apicalis, Sharp, fig. 182, Copelatus sulcipcnnis , Cast., fig. 187, and aubcei , 
Montr., fig. 188, pi. xv. Mate bicarinatus , Say, fig. 192, Coptotorius inter- 
rogate, Fabr., fig. 193, Scutopterus horni , Crotch, fig. 196, Rhantus 
cicurus, Fabr., Colymbetes sculptilis, Harr., Meladema lanio , Fabr., Hyde- 
rodes shuckardi, Hope, figs. 198-201, pi. xvi., H. shuckardi, $ , fig. 202, 
Dytiscus hybridus , Aube, fig. 203, lapponicus, Gyll., figs. 204 & 205, Hyda - 
ticus bihamatus and petiti, Aub6, figs. 207 & 208, Acilius seniisulcatus , 
Aub4, figs. 209 & 210, Thermonectus marmoratus, Hope, and basilaris , 
Harr., figs. 211 & 212, pi. xvii., Sandracottus hunteri, Crotch, var. chevro- 
lati , Aube, fig. 214, Graphoderes adamsi, Clark, and verrucifer, Sahib., 
figs. 216 & 217, Eretes australis, Er., fig. 218, Cy bister owas, Cast., limba- 
tus, Fabr., and japonicus, Sharp, figs. 223-225, pi. xviii. 
Times of appearance of rare Hydradephaga ; Hey & Power, Ent. xv. 
pp. 211 & 212. 
Fresh-water bivalves carried about by Dytiscidce ; Darwin, J. North- 
ampton Soc. ii. pp. 69 & 70. 
Sharp, Biol. Centr. Am. Col. i. (2), figures Agabus americanus, Rhantus 
atricolor , Thermonectus nigro-fasciatus, and Megadytes fallax , Aubd, and 
Cy bister fimbriolatus, Say, pi. i. figs. 8, 11-14. 
Hydroporus Jlavipes, 01., discussed, and varr. octo-lineatus, portalegrensis, 
Portugal, manducus, Sardinia, and montenegrinus, from Montenegro 
described : also II. distihguendus, Desbr., var. estrellensis from Estrella ; 
Schaufuss, Nunq. Ot. iii. pp. 558 & 559. II. fairmairii, Lepr., = bran- 
nani, Schauf., & ? = vesi^MS^Fairm.; nec Gebl. ; id. Bull. Soc. Ent. Fr. 
(6) ii. p. lxxxiv. H. bceticus , Schaum, and Herophydrus ( Hydroporus ) 
guineensis, Aub6, noticed ; Ragusa, Nat. Sicil. i. pp. 248 & 249. H. bryan- 
stoni, Sharp ( nec Clark), described ; Tr. Dubl. Soc. (2) ii. p. 342 : renamed 
Desmopachria mutata, Sharp, Biol. Cent. Am. Col. i. (2) p. 18. 
Ilydrocanthus lineatus , Wehncke (nec Suphis lineatus, Horn, which is 
congeneric), renamed Canthydrus mexicanus , and refigured ; Sharp, l. c. 
