43. Enchelis Retrograda.
E. hyalina, antice angustata, apice globulari. [Plate XXV.] Fig. 11 and 12. Transparent enchelis, the fore-part rather smaller, and terminating in a small globule.
It has a gelatinous transparent body; no visible intestines, though a pellucid globule is discoverable near the hinder-part; the body is thickest in the middle, and grows smaller towards each end. It generally moves side-ways, sometimes in a retrograde manner; and if it be obstructed in its motion, draws itself up, as it is represented at Fig. 11.
44. Enchelis Festinans.
E. cylindrica oblonga, obtusa, antice hyalina. Oblong cylindrical enchelis; the ends obtuse, the fore-part transparent.
The body is round, of an equal size throughout, and both ends obtuse; more than half the length is without any visible intestines, the lower end full of vesicular, pellucid, minute globules; a large globular vesicle is also to be found in the fore-part; it moves quickly from one side to the other, in a reeling or staggering manner. It was found in sea water.
45. Enchelis Farcimen.
E. cylindracea curvata utrinque truncata. A cylindric enchelis, crooked and truncated at both ends.
The body of this is cylindrical, about four times as long as broad, even, truncated at both ends, the intestines opake, and not to be distinguished from one another; it turns the extremities opposite ways, so as to form the figure of an S. It is to be found in water that has stood for some time, though but seldom. Joblot found it in an infusion of corn centaury or blue-bottle; it moves in an undulatory manner, but very slowly.