The Microscope. 203 



head are ciliated, the cilia being very long and fine. They are 

 arranged in two transverse or encircling series, those of the anterior 

 extending backward, while those of the posterior project anteriorly 

 and habitually vibrate in that direction. The lateral lobes are merged 

 into the constricted region which forms a conspicuous neck-like part 

 and equals or exceeds in length that of the head. It is movable and 

 extremely flexible, the Dasydytes continually bending it fi-om side to 

 side in the search for food, or lifting it upward or flexing it toward 

 the ventral surface. It can not be rotated; so far as I have seen 

 rotation is accomplished only by a partial revolution of the whole 

 body. The movement of cervical flexure is made chiefly when the 

 Dasydytes throws the body on the back, almost invariably turning 

 this somersault by flexing the neck under the ventrum and lifting 

 the rest of the body forward. The feat is seldom performed, and 

 the position is retained for a short time only, thus making a study 

 of the ventral surface prolonged and tedious, as the observer can 

 have only the most momentaiy and unsatisfactory glimpses at its 

 appendages. 



The body proper is ovate, the dorsal surface convex and the 

 ventral flattened. From each side of the anterior region near the 

 base of the neck, from each shoulder, if I may so express it, there 

 arise from four to six large, bristle-like setse, each of which equals or 

 exceeds the entire animal in length. These appendages originate at 

 equal distances apart on the lower surface of the lateral borders, arch 

 upward above the dorsal region, the group on the right-hand side 

 extending above the body and obliquely backward toward the left- 

 hand border, while the sinistral cluster, originating in the same way 

 on its side, extends similarly toward the right-hand margin, one 

 group crossing the other above the postero- dorsal region, and both 

 projecting obliquely for a considerable distance beyond the rounded 

 extremity of the body. (Fig. 1.) The setae are most robust at 

 their points of origin, near which they usually exhibit an irregularly 

 sigmoid curvature, thence tapering and evenly curving, without 

 abrupt bends or any signs of furcation, to their distal extremities. 

 They seem to rise directly from the body without the intervention of a 

 plater, scale or cuticular thickening of any kind. The Dasydytes can 

 slightly separate those of each cluster, but further than this I have 

 not observed that it has any control over them. Occasionally they 

 are to be seen extending irregularly along the animal's sides, thus 

 giving it an untidy and disheveled appearance, but whether or not 

 this arrangement is voluntary I do not know. What their function 



