176 MICROSCOPIC FAUNA. 



tapering foot, and crowned with a diadem of five curved crystal 

 arms, each fringed with the daintiest crystal plumes, while the 

 whole is set in a transparent vase of cylindrical shape and most deli- 

 cate texture. If startled, it will close up its five arms, and retreat into 

 its tube for safety, but soon emerge again. The crown is almost 

 a sphere. The setae which fringe the arms are much longer than 

 they at first appear; they are gracefully curved, and taper off 

 into lines of exquisite fineness. Those of one arm interlace with 

 those of the arms at either side of it, so as to form a transparent 

 living cap of the finest network, into which it is very easy for 

 its prey to enter, but out of which it is hardly possible for anything 

 to pass without touching some part of those sensitive meshes. 

 The instant anything enclosed within the arms does this, band 

 after band of the cilia lashes at the runaway, a swift current is set 

 up, and the captive is thrown back into the vortex which draws 

 it into the buccal aperture, through which it passes between the 

 jaws of the mallei, and then into the stomach (Fig. 13). If a 

 Stephanoceros, fully expanded, is placed in a favourable position 

 with the crown turned towards the observer, about 45*^ from the 

 plane of vision, and a ray of oblique hght directed upon the 

 specimen, the cilia will be seen to curve inwards, the cilia of one 

 horn of the crown almost meeting the cilia of the proximate horn, 

 and curving inwards so as to render ingress into the space enclosed 

 by the crown exceedingly easy, but egress most difficult. Occasion- 

 ally, one can detect a fitful ciHary wave running round the top of 

 the coronal cap, but only for the briefest duration. 



I have touched upon only a few of the microscopic organisms 

 of our canal, and with those few that have been mentioned all are 

 doubtless tolerably familiar. But even with the most familiar, 

 there is still much to study, and more to discover. As, 

 for instance, what seasons are most favourable to one kind, 

 and what to another ; what Fauna come out more abundantly in 

 sunshine, and what in shade ; which are nocturnal in their habits, 

 and which love the light of day ? And, with all that yet lies before 

 us to discover in microscojiic Fauna, we may all deem ourselves 

 fortunate in having a canal so replete with treasure within such 

 easy reach. 



