EUTIMA LIMPIDA. 



117 



tive cavity (c, Fig. 175) is very short ; it is situated at the extremity 

 of the narrow flexible sac, extending from g to c, Fig. 175, and termi- 

 nates in a flat quadrangular disk (d, Fig. 175), which is sometimes 

 folded in the shape of forceps, although generally kept stretched out 

 flat, like the sucking disk of a leech ; in the centre of this disk we find 

 the actinostome, which is a very small rosette-shaped opening, with 

 four loops. The genital glands (o, Fig. 175) are narrow ; they rise 

 almost from the circular tube, and foUow the chymiferous tubes along 



Fig. 178. 



the gelatinous prolongation of the disk, nearly to the level of the veil, 

 (o'. Fig. 175.) The tentacles are hollow and have no swelling at the 

 base (Fig. 176), the walls being thicker and tapering gradually to the 

 extremity. In the marginal capsules (Fig. 177), which are so large 

 that they can be seen with the naked eye, there are from twelve to 

 thirteen granules arranged in a circle near the periphery of the capsule. 

 The rudimentary tentacles (f. Fig. 178) are mere triangular expansions 



Fig. 1 75. Magnified -view of the proboscis and genital organs, g, terminal point of gelatinous 

 prolongation of the disk ; o, part of genital organs extending along the bell ; o', terminal point of 

 genital organs along the gelatinous prolongation of the bell ; c, digestive cavity ; rf, actinostome in 

 its usual mode of expansion. 



Fig. 176. Magnified portion of the circular canal, with a primary tentacle and tentacular cirri, 

 to show the rudimentary tentacles between the chymiferous tubes and the capsules, c. 



Fig. 177. Magnified marginal capsule, showing the circular arrangement of the granules. 



Fig. 1 78. StiU more magnified view of the rudimentary tentacles, c, circular tube ; i, rudi- 

 mentary tentacles. 



