Fig 
S: 
. 32 
Fig. 
W229 
. 30. Diagram of pieces surrounding middle coxal cavity in Hydrocanthus (Dytisci fragmentati) ; 
31 
34 
ig. 45 
ig. 46. 
ig. 47. 
On Aquatic Carnivorous Coleoptera or Dytiscida. 
. Prosternal process of Canthydrus, (C. grammicus). 
. Prosternal process of Hydrovatus. 
. 20. Prosternal process of Platynectes. 
. Prosternal process of Neptosternus. 
. Prosternal process of Laccophilus (Dytiscus maculosus, Germ.) 
. Mesosternum of Dytiscus (D. marginalis, L.) ; a, episternum ; 5, epimeron ; c, portion of margin 
of middle coxal cavity ; d, medisternum. 
- Mesosternum of Hydrocanthus (H. atripennis), one side removed ; lettering as in fig. 23. 
. Middle coxal cavity looked into, and seen laterally, of Eretes; a, mesosternum ; 5, metaster- 
num ; ¢, vacant space forming a foramen of communication with the cavity of other side of 
body. 
. Same parts in Hydaticus rimosus. 
. Same parts in Deronectes (Dytiscus assimilis, Payk.) 
. Same parts in Deronectes (Hydroporus luctuosus, Aubé). 
. Same parts in Hydroporus (Hyphydrus memnonius, Nic.) 
a, mesosternum (medisternum) ; 0, its episternum ; ¢, its epimeron; d, episternum of meta- 
sternum, with exposed and thickened anterior margin simulating an additional piece ; e, 
metasternum ; f, coxal cavity. 
. Similar diagram of Laccophilus (aiso Dytisci fragmenti). 
. Similar diagram of Colymbetes (Dytisci complicati), but with epipleura represented ; a, meso- 
sternum ; 6, its episternum; c, epipleura; d, metathoracic episternum with incrassate and 
exposed anterior border; e, metasternum ; /, coxal cavity ; g, mesothoracic epimeron. 
g. 33, Diagram of the middle of undersurface in Silphomorpha (Carabide, Pseudomorphini) ; @, meso- 
sternum proper (medisternum) ; 6, its episternum ; ¢, its epimeron ; d, metasternum ee mits: 
episternum ; /, its epimeron ; g, internal lamina of hind coxa; h, external lamina of hind 
coxa ; 2, first ventral segment ; /, middle coxal cavity. 
. Diagram of same parts in Procrustes (Carabide, Carabini) ; in this the parts of the side pieces 
usually covered by the wingcases are introduced; and /f, indicates the external portion of 
the metathoracic episternum to which the membranous epimeron is attached, the suture 
between these two pieces being really placed on the inner face of the episternum and thus 
concealed ; otherwise lettering as in fig. 33. 
. 35, Diagram of same parts in Cybister (Dytiscus reeselii) ; the lateral portions are covered by the 
wingease when this is closed ; lettering as in fig, 33. 
Idem 
38. Idem 
5 OY), Idem 
. 40. Idem 
4]. Idem 
, 42. Idem 
43. Idem 
99 
?? 
. 36. Metasternum and hind coxx of Amphizoa. 
ig. 37. 
Pelobius. 
Suphis. 
Noterus. 
Hydrovatus, 
Queda. 
Laccophilus. 
Hyphydrus, on the right side of this figure, the first ventral 
segment, and the external parts of the pieces usually concealed by the wingcase are 
introduced. 
g. 44. Metasternum and hind coxe of Methles. 
. One side of metasternum and hind coxa of Celambus. 
Idem 
Hind coxa of Hydroporvs, 
of Paroster. 
