NOTODELPHYS. 
239 
of three joints, and having the setae which spring from 
them partially plumose. 
The feet are four pairs in number, and are all alike (f. 7 g). 
They consist, each of two branches, springing from a basal 
lamina of two joints, and each branch composed of three 
articulations, copiously furnished on their inner edge with 
plumose setae. Each of these feet is attached to a cor- 
responding segment of the thorax. 
The abdomen is somewhat cylindrical, and terminates 
in two caudal appendages, each carrying at the extremity 
four short, plumose setae. The fourth segment of the body 
is of a peculiar formation, having in its dorsal portion a 
large hollow receptacle for receiving and containing the 
ova. In the angle between this sac and the upper surface 
of the ring, of which it forms a part, there is an opening 
by wdiich the eggs escape when they have arrived at 
maturity. At first emerging from the ovum the young- 
animal is very like in form to the young of the Cyclops ; 
but its changes have not been traced from this larva state 
to its full growth. 
Hah . — Belfast Bay ; Strangford Lough, county Down ; 
W. Thompson and G. C. Hyndman, Esqrs. Killery 
Bay, county Galway ; R. Ball and W. Thompson, Esqrs. 
Bangor, county Down ; R. Paterson, Esq. Glandore 
Harbour, county Cork, Dublin Bay, and Southampton 
Water; George J. Allman, Esq. In the branchial sac of 
the Ascidia communis . 
