THE LIFE-HISTORY OF HTDROBIUS FUSCIPES, L. 321 



Packard (1898, p. 181), although not describing his views, gives the figures of Kolbe (vide 

 figs. 203 and 204) according to which the sclerites of segment 8 have disappeared, the 

 segment being only represented by a length of connective tissue between the sclerites 

 of segments 7 and 9. Peytoureau (1895), on the other hand, only recognises as 

 segments those regions bearing one or more sclerites, and he considers segment 8 to be 

 represented by both tergite and sternite, while segment 9, the terminal one, is represented 

 only by a sternite. Packard treats Peytoureau's segment 8 as being really the tergite 

 of segment 9 (which he considers has no sternite) and the sternite of segment 10, which 

 has no tergite, and he calls Peytoureau's 9th sternite the external lobes of the penis. 



Henneguey (1904, p. 185) has followed Peytoureau, as he states that the repro- 

 ductive organs of the males of Coleoptera are always found upon the posterior border of 

 the 9th sternite, and he gives one of Peytoureau's figures. It is difficult to find any 

 justification for the view of Kolbe and Packard, since the connective tissue region 

 which they treat as segment 8 is no better marked than a similar region between their 

 segment 10 and the sclerites of the penis. There is, however, this to be said for their 

 view, the sclerite they describe as the external lobes of the penis, which is Peytoureau's 

 9th sternite, certainly functions as part of the penis. In copulation the posterior 

 segments of the abdomen and also the penis — which in a state of rest are telescoped 

 within the other abdominal segments — are protruded, and the penis, together with the 

 external lobes (Kolbe), i.e. the 9th sternite (Peytoureau) is bent downwards and to 

 the right or left according to the position of the male on the back of the female, and a 

 distinct kink is visible at the bend. The region beyond the kink, i.e. penis and external 

 lobes, bends right round until it comes to lie beneath the abdomen ; that is, it turns 

 through an angle of 180° and the dorsal side remains dorsal during copulation. 

 Mr Donisthorpe (Ent. Rec, xii. 291, 1900) observed the same fact in Hydrophilus 

 piceus, L. 



The Female Sexual Armature. (Pigs. 12-14.) 



Peytoureau (I.e., plate xx.) gives a drawing of the female armature of Hydrophilus 

 in what he describes as a state of activity, and he says (I.e., p. 154) that the 8th 

 sternite " porte a son bord posterieur mamelonne deux apophyses simples, courtes, 

 dirigees en arriere, armies a leurs extremites de poils sensitifs, cachees par le huitieme 

 urite et deux autres apophyses laterales plus longues egalement terminees par des poils 

 sensitifs " ; and he further says (I.e., p. 155), " C'est apres le septieme sternite que s'ouvre 

 l'oviducte simplement membraneux. L'articulation tergo-sternale du huitieme urite a 

 lieu au point x (plate xx. fig. 3) ; elle est assez lache, grace a la presence d'une 

 membrane d'union." 



If this is a correct statement for Hydrophilus, then Hydrobius appears to differ 

 very decidedly, as, from my observations, it is difficult not to associate the armature 

 with the 8th rather than with the 7th segment — a condition which, according to 

 Peytoureau, exists in Dytiseus. 



