BIHANG TILL K. SV. VET.-AKAD. HANDL. BAND. 5. N:O 16. TY 
oviduct and penis serve evidently to give strength to their 
respective organs, and to direct the motions of the penis 
and the ova. Only the exterior sheath of the oviduct is 
attached to the body-wall with its lower or exterior end, 
the other sheaths being all free and movable round the 
penis proper. The copulative organs are always surrounded 
by muscles which generally are straight (fig. 2), but some- 
times as in the genus Camptodrilus even spiral, (fig. 5 & 6). 
Their lower end is then fixed to the body-wall from where 
they coil themselves spirally round the copulative organs, 
and, when reaching the top of the oviduct, return on the 
same way inside the outer spiral down to the exterior orifice 
of the oviduct, where they are found to be attached to the 
same. 
What work such peculiar muscles can perform is easily 
understood. When relaxed their upper or interior end forms 
a kind of a wide funnel-shaped opening (fig. 6), especially 
adapted, as it seems, to the capturing of the ova, when 
foating in the perigastrie cavity of the body. And when 
once caught and introduced in the oviduct, a few succes- 
sive contractions may suffice to push them towards and finally 
through the genital porus. On the same way these muscles 
may also facilitate the projection of the penis or penis sheath. 
The lowest or most primitive form of the oviduct is 
found in Telmatodrilus. It consists here simply of a fold 
in the body-wall, which in the middle is furnished with a 
small circular opening, through which the penis in adult 
specimens is projected. In this genus we find a muscular 
penis-sheath, but no interior sheath belonging to the oviduct. 
TUBIFICIDAE. 
Subfamily 1. TELMATODRILINI Nn. 
The atrium is furnished with several prostata-glands, 
(fig. I atr & pr). The vascular system is nearly similar to 
that of the Tubificini, but differs in having no distinct pul- 
sating heart, but 5 pair indistinetly pulsating ones in the 
segments 6 to 10. The ventral vessel is not strictly ventral, 
but pushed towards one side of the body and so near to 
the dorsal vessel, that both really seem to be situated on the 
