22 THE EOTIFERA. 



crimson, and the eye of a rich ruby-red ; the whole giving a most attractive appearance 

 to the animal, which is, moreover, very vivacious in manner. 

 Length, ^V inch. Habitat. Lacustrine. P.H.G.] 



NOTOMMATA TORULOSA, Dujardin (40), (PL XXXII. fig. 20). 



Lindia torulosa Dujardin (40) ; Cohn (20). 



Notommata roseola (?) . . . . Perty (124). 

 Notommata tardigrada (?) . . . Leyclig (110). 



SP. CH. Body cylindrical, ivith several transverse constrictions, slightly tapering 

 at both ends, rounded in front ; auricles evertile and pedunculated ; toes very short; 

 brain long, cylindrical, and ending in a rounded dark mass which is white by reflected 

 light. 



It is, I think, highly probable that a Rotiferon with these specific characters has been 

 described as a new species by three separate observers in succession, and has been named 

 differently by each of them. I shall follow Leydig's and Cohn's descriptions, which agree 

 in almost every particular ; only Leydig never saw the creature protrude its auricles. 

 -The Rotiferon has a worm-like body ; a long, spheroidal mastax with forcipate trophi ; 

 a rather long oesophagus ; a long, straight stomach, ending in a short, clear, intestine ; 

 and a conspicuous, small contractile vesicle. Neither Leydig nor Cohn could see the 

 vibratile tags. The nervous ganglion is of the generic pattern, a long cylinder with a 

 rounded end stretching from the fore part of the head, over the mastax, to the top of the 

 stomach. This rounded end is, says Cohn, full of strongly refractive particles, which are 

 greyish-white by reflected light, and dark by transmitted light. In front of them lies, in 

 adults, a black eye-spot ; which in young individuals is red. Each auricle, according to 

 Cohn, is a roundish ciliated knob on a thin peduncle. The main differences between 

 Cohn and Leydig are due to the latter having had no opportunity of seeing the auricles, 

 and the former having overlooked some very fine short cilia which fringe the mouth, 

 a slit on the ventral surface of the head. A minor difference is that Leydig's animal was 

 ^ s inch, while Cohn's was ^ inch, and Pujardin's T V inch. 



Cohn is of opinion that Perty's N. roseola is most probably the same animal ; and in 

 this I agree with him. It is true that his figure shows a stouter animal, with cylindrical 

 auricles ; but his description agrees closely with those of Cohn and Leydig, while all his 

 figures of Rotifera are rough and unsatisfactory. Both Cohn and Perty noticed that the 

 body had a faint pink tinge. This Rotiferon belongs evidently to the genus Notommata, 

 as denned by Mr. Gosse (not Ehrenberg), and I have of course added the specific name 

 torulosa devised by its discoverer Dujardin. 



Length. Maximum observed, -^ inch ; minimum, ^ s inch. Habitat. Among the 

 slime of the Maine (Leydig) ; pools and watercourses of the Aar towards Belp (Perty). 



NOTOMMATA ONJSCIFOEMIS, Perty (124), (PI. XXXII. fig. 19). 



SP. CH. Body very flatly arched, so as to resemble an Oniscus ; trophi stout; 

 uncus with many teeth ; auricles round and small ; toes rather long. 



Perty says that the cilia lie between the auricles ; that the eye is red ; that the uncus 

 has many teeth ; and that he could see no organs, through the thick, striped, though 

 hyaline coat, but the eye, mastax, and alimentary canal, Mr. Gosse (vol. ii. p. 23) has 

 noticed the similarity of its cross-section to that of his N. pilarius. 



Length, T ] 4 - inch. Habitat. Pools and watercourses of the Aar, towards Belp ; 

 among confervae and charse (Perty), 



N. REINHARDTI = _F. Beinhardti, Ehrenberg (42). SP. CH. 'Body fusiform, truncated 

 in front ; a long cylindrical retractile foot, with short toes. This is very closely allied 



