38 Ins. 
COLEOPTERA. 
Siam, denticulatus , Australia, flammulatus y China, p. 359, inornatus , West 
Australia, impressus , New Zealand, Australia, plicatus , pi. x. fig. 127, 
p. 360, huttoni, New Zealand, p. 361, mundus , bi/or mis, p. 362, dispar , 
Australia, occultus, Hedjaz, perforatus, China, p. 363, dilutus, Siam, p.364, 
uruguensis , Uruguay, crassus , p. 365, atomgrius , Brazil, texanus , Texas, 
p. 366, lynceus , Guatemala, p. 368, and discoid alls, Parana, p. 369 ; add 
21. discedens , Mexico, p. 19, hydrovatoides , fig. 5, germanus, fig. 6, Guate- 
mala, p. 20, quadrisignatus , Mexico, Guatemala, quadrinotatus, Mexico, 
p. 21, latifrons, Guatemala, substriatus, Mexico, p. 22, subornatus, Mexico, 
Guatemala, p. 23, abjectus , Mexico, spretus , obtusus , p. 24, and elongatus, 
fig. 7, Guatemala, p. 25, id. Biol. Centr. Am. CoJ. i. (2) pi. 1. 
Huxelhydrus , id. Tr. Dubl. Soc. (2) ii. pp. 369 & 854. Allied to 
Bidessus ; prosternal process elongate, parallel-sided ; intercoxal process 
of metasternum not attaining the mesosternal fork ; hind tibiae with a 
distinct slender basal portion ; coxal lines shorter than the prosternal 
process. Type, H. syntheticus , sp. n., 1. c. p. 369, pi. x. fig. 129, N. Aus- 
tralia, New Zealand. 
Tyndallhydrus, id. 1. c. pp. 370 & 854. Affinities doubtful, placed after 
Huxelhydrus ; prothorax narrowed behind ; prosternal process prevented 
by the contiguous and intervening middle coxae from attaining the meta- 
sternum. Type, T. caraboides, sp. n., 1. c. p. 370, pi. xi. fig. 130, Algoa 
Bay. 
Andex , id. 1. c. pp. 371 & 855. Allied to Hyphydrus ; prosternal pro- 
cess abbreviate, its concealed extremity not extending outside the middle 
coxae, and not reaching the metasternum ; prothorax much narrower than 
the rest of the body, so that the outline at the shoulders is much inter- 
rupted. Type, A. insignis , sp. n., 1. c. p. 371, pi. xi. fig. 131, Cape of Good 
Hope. 
Hydropeplus, id. 1. c. pp. 372 & 855. Placed after Andex; terminal 
joint of front tarsus quite twice as long as the second joint ; head 
rounded in front ; elytra at the shoulder of the epipleura, with a fossa 
limited behind by a distinct raised line. Type, Hydroporus trimacu- 
latus , Cast, (figured, pi. xi. fig. 132). 
Primospes, id. 1. c. pp. 372 & 356. Placed after ffydropeplus ; head 
subtruncate in front ; the depression at the base of the elytral epipleura 
not limited behind by a raised line. Type, P. suturalis , sp. n., 1. c. pi. xi. 
fig. 133, Cape Town. 
Ccelhydrus, id. 1. c. pp. 373 & 856. Placed after Primospes ; epipleura 
much narrowed from the shoulder to the hind margin of the first ventral 
segment ; behind that very slender, and therefore nearly parallel ; last 
joint of the front tarsus about as long as the third joint ; prosternal pro- 
cess reaching intercoxal process of the metasternum. Type, C. brevi- 
collis, sp. n., 1. c. p. 373, pi. xi. fig. 134, S. Africa. 
Darwinhydrus, id. 1. c. pp. 373 & 857. Placed after Ccelhydrus ; epipleura 
of elytra becoming gradually narrower from the shoulder to the 
extremity ; outline of thorax and elytra quite continuous, the latter 
acutely costate. Type, D. solidus , sp. n., 1. c. p. 374, pi. xi. fig. 135, Cape 
Town. 
Sternopriscus , id. 1. c. pp. 384 & 858. Affinities uncertain, placed after 
