Mr. E. Forbes on two Sjjecies 0/ Cydrpi)e. 147 



small canal proceeding to the other extremity of the animal, 

 and opening in the little funnel-like cavity of the anus. At 

 about one-fourth the length of the animal on each side the 

 anal half are the openings of the two filamental cavities. 

 Each cavity is a cul-de-sac, in which a long filamental arm is 

 lodged, attached to a triangular process projecting from the 

 inner side of the base. The filaments are not rolled spirally, 

 but packed irregularly in the cavities, and are jerked as it 

 were out of the body by their contraction. In the first spe- 

 cies the filamental cavity is shorter, though wider than in 

 the second, but the filaments themselves are much longer. 

 Each filament is furnished on one side with a number of small 

 filaments coiled spirally like the tendrils of a pea. When the 

 main filaments are ejected from the body the little filaments 

 begin to uncoil, not simultaneously, but separately, those 

 about the centre generally uncoiling first. The two main 

 filaments appear to be tubular. They are not ejected from 

 the body simultaneously, at least in all my specimens they 

 w'ere sent out alternately. 



On making sections of the animal we find the following ap- 

 pearances. The stomach is compressed laterally and four- 

 lobed, the two cross lobes being smallest ; the filamental ca- 

 vities are cordiform towards the base in consequence of the 

 projecting pedules of the filaments. From the basal angles of 

 each filamental cavity proceed six canals, two to the stomach, 

 meeting at the extremity of the cross lobes, and four to the 

 ridges of cilia. Two of the latter and one of the former ca- 

 nals meet at each of the basal angles. The canals to the ci- 

 liferous ridges probably communicate with longitudinal canals 

 at their bases. The rest of the body is homogeneous and solid. 

 Round the mouth is a white thread-like circle, but I could ob- 

 serve no filaments branching from it : it is not connected wdth 

 the terminations of the ciliferous ridges. This circle, judging 

 from analogy, is probably nervous. 



When an individual of either species is placed in a vessel 

 of sea-water, it often projects its long filaments upwards, itself 

 resting at the bottom of the vessel. At other times it darts 

 upwards with great velocity, drawing its long filaments after 



m2 



