On Aquatic Carnivorous Coleoptera or. Di/tiscidce. 985 



Fig. 48. Internal laminie of liiml coxre of Hydroporus diver.siconii.s. 



„ Hydroporus oblongus. 



„ Agabiis (Dyfciscus bnmneus). 



„ Agabus (Dytiscus bipustiilatus). 



„ Platambus (Dyliiscus maculatu.s). 



,, Agabiuus. 



„ Copelatus. 



„ Agabetes. 

 Fig. 56. External lamina and wing of mctasteniiun of Agabus (Dytiscus uliginosus). 



Fig. 67. „ „ „ Agabus (Dytiscus abbreviatus). 



Fig. 58. „ ,, „ Platambus (Dytiscus maculatus). 



Fig. 59. „ „ „ Copelatus. 



Fig. GO. Hind coxa and one side of metasteruum of Prodaticus. 



Fig. 61. „ „ „ Hydaticus. 



Fig. 62. „ „ „ Thermonectes. 



Fig. 63. „ „ „ Acilius. 



Fig. 64. „ „ „ Eretes. 



PLATE VIII. 



Fig. 65 Lateral view of articulations at side of breast of Eretes ; n, metatlioracic episternum ; b, meta- 

 tlioracic epimeron ; r, 1st ventral segment; d, bind coxa; e, wing of metasternum : in thi.s 

 fig. and in fig. 66, the portion on the left of the dotted line is covered by the wing-case in the 

 condition of repose. 



Fig. 66. Lateral view of articulations at side of Ijreast of Cybister (Dytiscus roeselii, Fab.) ; lettering as in 

 preceding fig. 



Fig. 67. Ventral segments of Dytiscus (D. marginalis.) 



Fig. 68. Idem ,, Pelobius (Dytiscus tardus.) 



Fig. 69. Dorsal aspect of middle and hind body of Cybister (Dytiscus roeselii, Fab.), with the left wing- 

 case and wing removed ; a, right wing-case ; b, scutellum ; c, mesonotum ; (/, point of articu- 

 lation of wing-case : e, angle of mesothoracic episternum ; f, upper edge of mesothoracic 

 epimeron ; tj, upper (semicorneous) portion of metathoracic episternum ; /;, idem of metatlio- 

 racic epimeron ; i, line of attachment of wing ; k, jiieces of metanotum ; I, trochanter of 

 articulation between various pieces; ///, hind border of metanotum, where is situate the 

 metathoracic breathing aperture ; 1 to 8, dorsal plates of hind-body or abdomen ; 1* to 6*, 

 upper edges of ventral plates of hind-body ; s to s', abdominal stigmata or breathing 

 apertures. 



Fig. 70. Superior oblique lateral view of i-ight side of hind-body, and metasterno-coxal articulation of 

 Dytiscus latissimus ; a, portions of metanotum ; b, metathoiacic epimeron ; c, angle of hind- 

 coxa ; (/, metathoracic stigma ; e, side j^iece of fii'st ventral segment ; /', stigmatic rugte ; 

 g, fii-st abdominal stigma ; 1 to 8, dorsal plates of hind-body : this diagram is made from a 

 specimen distended by stufiing with cotton-wool, so that the membranous portions are shown 

 as fully as the corneous. 



Fig. 71. Outline of front foot of Hyphydrus $, (Dytiscus ovatus, L.) 



Fig. 72. Outline of front foot of Hydroporus S- 



Fig. 73. Outline of front foot of Necterosoma. 



Fig. 74. Anterior tibia and tarsus of Noterus ^ (after Sohiodte, Dan. El. XVIII, A), 



