C. cylindrica, antice subtruncata, postice obtusa, bimucronata. Cylindrical cercaria, the fore-part somewhat truncated, the lower part obtuse, finishing with two small points.
A cylindrical opake animalculum, with two small points at the lower end, moveable, yet rigid, and placed at some distance; when in motion, the body appears to be surrounded with rows of small hairs separated a little from each other. It was observed in salt water.
133. Cercaria Crumena.
C. cylindraceo-ventricosa, antice oblique truncata, cauda lineari bicuspidata. Cylindrical, ventricose cercaria, the fore-part obliquely truncated, the tail linear, terminating with two diverging points.
The body is ventricose, cylindrical, thick, and wrinkled; the lower part small, the upper part terminates in a small, straight neck, like that of a pitcher; the tail terminates in two diverging points.
134. Cercaria Catellus.
C. tripartita, cauda bisecta. Three-parted cercaria, the tail divided into two parts.
This animalculum is more complex in its form than many others; it has a moveable head, which is affixed to the body only by a point; an abdomen, which is not so wide, but twice as long as the head, replete with intestines; and a tail which is shorter than the head, narrower than the belly, and terminating in two bristles, which it can unite and separate at pleasure. It moves with vivacity, though without going far from its own place.
135. Cercaria Catelina.
C. tripartita, cauda bicuspidata. Cercaria distinguished into three parts, with a short forked tail.