120. Bursaria Bullina.
B. cymbæformis, antice labrata. Boat-shaped bursaria, the fore-part formed into a lip.
A pellucid crystalline animalculum, furnished with splendid globules of different sizes swimming about within it; the under-side convex, the upper side hollow, the fore-part forming a kind of lip.
121. Bursaria Hirundinella.
B. utrinque laciniata, extremitatibus productis. [Plate XXV.] Fig. 19.
Bursaria with two small projecting wings, which give it somewhat of the appearance of a bird, and it moves something like a swallow. It is invisible to the naked eye, but by the microscope appears to be a pellucid hollow membrane; no intestines are visible. a, the head; b, the tail; c, one of the wings.
122. Bursaria Duplella.
B. elliptica, marginibus inflexis. [Plate XXV.] Fig. 18. Elliptic bursaria with the edge bent in and out.
A crystalline membrane folded up, without any visible intestines, if we except a little congeries of points under one of the folds. It was found among duck-weed.