632 



SUPPLEMENT 



X. BURSARIA. A very simple, hollow, mem- 

 bra naceous worm. 



This animalcule takes its name from the 

 resemblance its bears to a purse, or bag. 

 Ein-enberg has noticed only one species, and 

 lias not decided as to the situation of the ge- 

 nus. 



Plate 35, fig. 60. The little swallow-like 

 Bursaria. " The form of this animalcule, by 

 a little effort of imagination, may be compared 

 to a bird, and its movements appear like the 

 flight of the swallow: hence its name. It is 

 found in stagnant water." 



BURSARIA SPECIES. 



\.Bursariatruncatella. Ventricose, the top trunca- 

 ted. 2. Bursaria bullina. Boat-shaped, the fore-part 

 formed into a lip. 3. Bursaria hirundinella. Described. 

 4. Bursaria duplMa. Elliptic, with the edge bent in 

 and out. 5. Bursaria globina. Spherical, very pellu 

 cid in the middle. 



XL CERCARIA. An invisible, pellucid worm, 

 wiih a tail. 



" If we consider the internal organization 

 of this genus, it comprehends a very wide 

 range; indeed, the different species vary so 

 much that it is difficult to give a general de- 

 finition of their characters with any degree of 

 accuracy." 



Plate 35. fig. 59. The Green Cercaria. 

 "This is a highly interesting creature: the 

 bright green colour of its body ; its diaphanous 

 extremities; its well defined orange brown 

 eye ; and the numerous transformations of its 

 form, render it a very interesting object for 

 the microscope ; in addition to which it is 

 easily procured, and managed with great fa- 

 cility. The length of the specimen was about 

 l-350th of an inch: Ehrenberg gives l-280th 

 of an inch as their length. The magnifying 

 power best adapted for viewing them, is from 

 300 to 500 times, in an achromatic." 



Plate 27, fig. 29. Cercaria inquieta. 

 This animalcule so frequently changes its 

 form, that it is not easy to describe it; it is 

 sometimes spherical, sometimes like a long 

 cylinder, at other times of an oval figure, white 

 and gelatinous; the tail is filiform and flexible, 

 the upper part vibrating vehemently; it has 

 no visible viscera. Two small dots, probably 

 the eyes, are sometimes distinguishable; and 

 occasionally there is seen a large circular 

 marking near the tail. 



CERCARIA SPECIES. 



1. Cercaria gyrinus. Round, with a sharp tail. 2. 

 t ercana mtba. Oval-shaped, convex, the fore-part ra- 

 ther acute, the tail round. 3. Cercaria inquieta. Des- 

 cribed. 4. Cercaria lemna. Mutable, somewhat flat- 

 tened, with an annulated tail. 5. Cercaria turbo. Glo- 

 bular the middle contracted, with a tail like a bristle. 

 6. Cercaria poduria. Cylindrie, the liind-psirt sharp 



i somewhat cloven. 7. Cercaria riridis. Described. 



i. Cercaria sell/era. Cylindrie, fore-part smallest, 



hind-part pointed. 9. Cercaria Jdrta. Cylindrie, fore- 

 part somewhat truncated, lower part obtuse, finishing 

 with two small points. JO. Cercaria cntmena. Cylin- 

 drie, ventricose, fore-part obliquely truncated, tail lin- 

 ear, terminating with two diverging {mints. 11. Cerca- 

 ria catellus. Three-parted, tail divided into two parts. 

 12. Cercaria catelina. In three parts, with, a short 

 forked tail. 13. Cercaria lupus. Cylindrie, long, the 

 tail furnished with two spines. 1 4. Cercaria wniiexlaris. 

 Cylindrical, annulated, with a projecting proboscis, two 

 small spines for the tail. 1.5. Cercaria forcipata. Cy- 

 lindrie, wrinkled, with a forked proboscis, which it can 

 extend or contract. 16. Cercaria pleuroncdes. Orbicu- 

 lar, the tail consisting of one bristle. 17- Cercaria tripos. 

 Triangular, two bent arms, and a straight tail. 18. Cer- 

 caria cyclidium. Oval, hind-part somewhat notched, 

 with a tail that it thrusts out at pleasure. 19. Cercaria 

 tenax. Membranaceous, fore-part rather thick, trunca- 

 ted, the tail three times shorter. '20. Cercaria discus. 

 Orbicular, with a bent tail. 21. Cercaria orbis. Orbi- 

 cular, with a tail consisting of two very long bristles . 

 22. Cercaria luna. Orbicular, the tail of two short 

 spines, fore-part hollowed like a crescent. 



XII. LEUCOPHRA. An invisible worm, pel- 

 lucid, and every where ciliated. 



Plate 35, fig. 54. The Bracelet Leucoplira. 

 This animalcule is shown with the inner 

 edge ciliated, sometimes the ciliae are disposed 

 on the- circumference. It is scarce. 



Plate 27, fig. 54. Leucoplira cornuta. 

 This creature requires to be observed some 

 time before its peculiar character can be as- 

 certained ; the body is composed of molecular 

 vessels, of a dark green colour ; for the most 

 part it is like an inverted cone, the fore-part 

 being wide and truncated, with a little promi- 

 nent horn or hook on both sides ; the hind-part 

 conical, every where ciliated, the hairs ex- 

 ceedingly minute ; those in the fore-part are 

 three times longer than the latter, and move 

 in a circular direction. The hinder part is 

 pellucid, and sometimes terminates in two or 

 three obtuse pellucid projections. This ani- 

 malcule will at one moment appear oval, at 

 another reniform, and ciliated at the fore part; 

 but at another time the hairs are concealed. 

 When the water evaporates, it dissolves or 

 breaks into a number of molecular vesicles. 



LEUCOPHRA SPECIES. 



1. Leucoplira conflictor. Spherical, opaque, with 

 movable intestines. 2. Leucoplira mamVla. Spherical, 

 opaque, with a small papillary projection. 3. Leuco- 

 plira virescens. Cylindrical, opaque, the lower part much 

 thicker than the upper part. 4. Leucoplira viridis. 

 Oval, opaque. .5. Leucoplira, lursata. Green, oval, the 

 fore-part truncated. 6. Leucoplira postliuma. Globular, 

 opaque, and covered with a kind of pellucid net. 7. 

 Leucoplira aurea. Oval, yellow, both ends equally ob- 

 tuse. 8. Leucoplira pc.rtusa. Oval, gelatinous, apex 

 obtusely truncated, one side sunk down. 9. Leu- 

 coplira fracta. Long, with ciliated angles, rather 

 flat. 10. Leucoplira dilatata. Smooth, changeable, 

 with a ciliated edge. 11. Leucoplira scentillaus. Oval, 

 round, opaque, green. 12. Leucoplira vcsiculifera. Oval, 

 with vesicular intestines. 13. Leucoplira globulifera. 

 Crystalline, of an oblong, oval shape. 14, Leucoplira, 

 pnliuhda. Oblong, oval, the lower end obliquely trun- 

 cated. 15. Leucoplira turbinata. Like an inverted cone, 

 and rather opaque. 16'. Leucoplira acuta. Oval, round, 

 with the apex acute, mutable, yellow. 1 7. Leucoplira 

 notata. Oval, round, with a black point at the edge. 

 18. Leucoplira Candida. Oblong, one end smaller than the 



