1903.] NATURAL SCIENCES OF PHILADELPHIA. 381 



of minute floating corpuscles within the body cavity which greatly ob- 

 scure the internal organs. F. coronetta Cubitt (PL XX, figs. 22-24) 

 and F. ambigua Hudson (PI. XIX, figs. 19-21) were the other species 

 studied, but ambigua in only a few individuals, so that for this species 

 my observations are unfortunately fragmentary. 



General form. — In all Floscularians there may be distinguished 

 the corona, trunk and foot (PI. XXI, fig. 37). The corona is in ante- 

 rior extension and enlargement of the trunk. In campanulata (PL XX, 

 figs. 27, 28, 31) it is largest, widely bell-shaped and prolonged into five 

 broad lobes, the dorsal of which is largest and longest, next the two 

 ventral lobes, and smaller than these the two lateral lobes. In this 

 species the corona is subject to considerable individual variations in 

 form, but is always much wider and fully as long as the trunk. In 

 ambigua (PL XIX, fig. 20) the corona is relatively smaller, and of its 

 five lobes the lateral pair are usually very small and often distinguish- 

 able only by the cilia which they bear. In conklini (PL XX, figs. 25, 

 26) the corona is more cylindrical, frequently considerably less than half 

 the length of the trunk, the lateral lobes also very small. In coronetta 

 (PL XX, figs. 22, 23) the lobes are more cylindrical and narrowed, 

 with enlarged (knobbed) tips, the dorsal one only slightly longer than 

 the others. 



The trunk is elongate and cylindrical, in conklini (fig. 25) more arched 

 on the ventral than on the dorsal side. The foot is an elongate proxi- 

 mal extension of the body, relatively longest in conklini and coronetta. 

 The foot ends in a peduncle by which the animal is firmly attached to 

 the surface of a water plant stem. This peduncle is much longer than 

 broad in campanulata (PL XXI, fig. 40) and cmibigua, little longer than 

 broad in coronetta (PL XX, fig. 24), and fully as broad as long in 

 conklini (fig. 26). These different species were all found attached to 

 MyriophyUuni, but to different parts of it, campanulata always to the 

 very finest outgrowths of the plant; conklini usually to the angles at 

 the bases of stems; ambigua and coronetta to larger stems. 



In all these forms the animal is surrounded by a gelatinous, elastic 

 tube (PL XXI, fig. 37, Tub.), with an anterior opening; in conklini 

 (PL XX, fig. 26) the tube is relatively largest and its outer surface 

 often covered with foreign particles, and in campanulata it is exceed- 

 ingly transparent and visually without any such adherent particles. 

 By a weak solution of methylene blue the tube quickly becomes colored 

 intensely; and this method of demonstrating it shows its form with 

 great distinctness. 



The animals are highly contractile, thanks to the strongly developed 



