PHILODINAD.E. 107 



This species I have met with on several occasions in the water from Woolston Pond, 

 though it cannot be considered other than rare. It is one of the larger species, being 

 equal to R. tardus in size, with which from its form and colour it may readily be 

 confounded. The colour, however, is a clearer amber, and the comparative absence of 

 the deep longitudinal folds of the skin gives to this species a bright translucency like 

 that of stained glass. It readily expands its wheels, which are normal but small. The 

 antenna, however, is of unusual dimensions both in thickness and length, equalling 

 R. macroceros in this respect. The organ, however, does not wag to and fro, in the 

 curious manner characteristic of that species ; nor does the animal squat down on its 

 hinder parts, concealing its foot. The antenna is fusiform, and carries a distinct joint 

 at its extremity, which is, I think, retractile ; but not tipped with setas that I could per- 

 ceive. The thick truncate frontal column bears, near its tip, two large, conspicuous 

 dark-red eyes, showing the animal to be a true Rotifer. The specific name (from 

 a-n-To/xai, to touch or test) alludes to the presumed function of the prominent antenna. 



Length. About ^ inch. Habitat. Woolston Pond (P.H.G.) : rare.— P.H.G.] 



R. mackueus, Schrank. 



(PL X. fig. 4.) 



Rotifer macrurus . . . Ehrenberg, Die Infus. 1838, p. 490, Taf. lx. fig. 7. 



,, „ ... Pritchard, Infusoria., 1861, p. 704. 



[SP. CH. Body white, hyaline at the ends, plump, suddenly attenuated to a slender 

 and very long foot; corona large; spurs small; frontal column long, cylindrical, 

 truncate ; dorsal antenna of moderate length ; eyes usually small and round ; teeth 

 two. 



This is a large and well-marked species, imposing and attractive. Its stout corona, 

 large wheels, and plump body are much like those of a Philodina ; it can be generally 

 recognized by the sudden break in outline between the trunk and the foot, by the great 

 length of the latter, and by the long stout column, which stands well up above the 

 expanded wheels. The spurs are unusually short for so large a Rotifer, being of about 

 the same length as the three toes. The foot consists apparently of eight joints, almost 

 all of unusual length. There is a short, but bulging neck. The distinction between 

 the stomach and intestine is often visible, and the rectum extends through (what 

 appears to be) the whole basal joint of the foot. There are two oval gastric glands, 

 as well as a pair of club-shaped glands in the foot. A small contractile vesicle can 

 be readily seen, and so, with some little difficulty, can the lateral canals and 

 vibratile tags. Dr. Leydig failed to make out these last, but both Dr. Bartsch (loc. 

 cit. Tubingen) and myself have seen three tags on each side. The nervous gangl on 

 has not been noticed. The shape of the eyes appears to be variable. Dr. Leydig 

 says that he met with some specimens in which the pigment spots were hemispheres 

 much cut out in front, and in others were lengthened out into a row of points 

 lying behind one another. The former had light-refracting bodies seated on them, 

 which the latter lacked. A pair of muscles, inserted into the neck, pass to the great 

 constriction behind ; another pair, inserted in the shoulders, pass down into the first 

 joint of the foot ; and a third pair start from near the same point as these last, and pass 

 to points where the first pair end. Each joint of the foot has at least two longitudinal 

 muscles on each side, which pass into the joints above them. Under strong pressure 

 the whole foot is seen to be crossed with transverse muscles of which at least twenty can 

 be counted. High pressure shows numerous muscles in the trunk also. These are in 

 the form of broad bands alternating with spaces of equal width. I saw the birth of a 

 young one twenty-four hours after it had (apparently) escaped from an oval membrane 

 into the body-cavity. It passed head-first through the cloaca in a few seconds. It was 



