92 M. L. Plate on Ectoparasitic Rotatoria 



a view which acquires the more probability because we not 

 unfrequeutlj see a viscid drop adhering to the orifice of the 

 efferent duct. 



The description of the adhesive glands of the foot may 

 perhaps be best appended to that of the skin, as they un- 

 doubtedly represent particularly strongly developed portions 

 of the subcuticular matrix. There are about six to eight 

 glands, each possessing a very long efferent duct traversing 

 the abdomen (figs. 1 and 7, /). The further the cell pro- 

 ducing the viscous slime is moved from the posterior pole of 

 the body the longer is its efferent duct, which contains a great 

 number of granules. The foremost viscous glands, which are 

 placed at the level of the female sexual aperture or even still 

 further forward, have several nuclei which belong to separate 

 cells; those situated further back, on the contrary, are uninuclear. 

 The efferent ducts of the different glands run, without 

 uniting, to the caudal extremity, the peculiar construction of 

 which may be seen from fig. 4. It forms a rounded tubercle, 

 the periphery of which is beset with a number of small 

 denticles placed in a row, and thus resembles the cog-wheel 

 of a machine. The mucus secreted by the glands is pressed 

 out through these prongs, by which means it frequently 

 acquires the form of short threads lying side by side. It is 

 not always easy to convince one's self of the construction of 

 the posterior extremity of the body, as, like the posterior 

 apparent segment itself, it can be introverted. "When this is 

 the case an adherent disk with thickened margins seems to 

 close the caudal extremity, which, according to Claus, is 

 actually the case in Seison. 



The alimentary organs consist of three sections — the buccal 

 cavity with the masticatory apparatus, the oesophagus, and 

 the stomach. The anterior extremity of the head may be 

 somewhat drawn in, and the small buccal aperture^ situated at 

 its extreme apex, is therefore not always equally visible. 

 "When we look down upon it from above, which, indeed, we 

 seldom have the opportunity of doing, we observe that around 

 it stand four tufts (fig. 5, t) of small rigid setse, which are 

 never moved, and evidently serve only for tactile purposes. 

 We shall perhaps not be mistaken if we regard these as the 

 last rudiments of the rotatory apparatus^ which is retained in 

 a more distinct form in Seison and in Paraseison ciliatus^ 

 hereafter to be described. From the side, of course, we see 

 only two [bundles of] tactile setge (fig. 6, t)j and even these 

 become inaccessible to observation, when the fore part of the 

 head is more or less introverted. The buccal aperture itself 

 has a rounded form only when the masticatory apparatus is 



