NOTOMMATAD.E. 23 



to Mr. Gosso's Notommata Theodora, if not ideutical with it. Eacli is of great trans- 

 liicency ; with a long, retractile, slender foot (equal in length to the trunk), minute toes, 

 and a red frontal eye on an ample brain. They differ, however, in their habitats and 

 habits. Theodora is a fresh-water species found among confervse in a mill-stream, and 

 " it darts along with headlong swiftness." BeinJiardti, on the contrary, is only half the 

 size of Theodora, is marine, parasitic on Sertularia and Gorijne, and " its motion is not 

 very lively." Length, -^\^ inch. 



N. CENTEURA, Ehreiibcvg (42). If Mr. Gosse's Copcus labiatus (vol. ii. p. 28) be 

 deprived of its lumbar spines, and of its extraordinary hp, we should have precisely 

 Ehrenberg's N. centrura; as, indeed, Leydig pointed out (110). Mr. Gosse thought it 

 impossible that so good an observer as Ehrenberg could have overlooked the lip ; and it 

 is very difficult to suppose that he could have done so. But his figure has evidently 

 been taken from an animal under pressure ; and shows what look very much like two 

 lumbar spines bent back, by the cover-glass, on to the body ; and so pressed as to divide 

 into the separate hairs of which they are composed. Under such circumstances the 

 great lip might have been hidden by the head ; and it is just possible that Ehrenberg 

 did overlook it. 



N. MELANOGLENA, N. MEGALADENA, N. SULCATA, Schvuirda (135). See note 1, Sup', 

 p. 8. 



Peoales Weeneckii, Ehrenberg (PL XXXII. fig. 18). 



Notommata Wcrneckii .... Ehrenberg (i'2) ; Balbiani (4, 5). 



SP. CH. Body fusiform, segmented by transversa folds, tapering continuousUj to 

 front and rear ; ventral ciliated face distinctly oblique ; a slightly decurved proboscis ; 

 toes small, straight, pointed : parasitic in galls of Vaucheria. 



Although Ehrenberg established the fact that a Eotiferon lives in excrescences on the 

 filaments of Vaucheria, he had no opportunity of studying the creature, as all his speci- 

 mens died before they were hatched. Professor Balbiani, however, was more fortunate ; 

 and he has given [loc. cit.) an admirable account of the animal, and its habits, accom- 

 panied by equally good drawings. It is from this account that the followmg remarks are 

 taken. 



The tubes of Vaucheria often bear two kinds of excrescences : the one, the organs of 

 reproduction ; the other, which are much larger, are generally club-shaped capsules, 

 nearly at right-angles to the stem, and of the same green colour. These are the habita- 

 tions of N. Werneckii, and Professor Balbiani is of opinion that they are the reproduc- 

 tive organs of the plant, stimulated into excessive growth by the action on them of the 

 sahva of the Eotiferon. (See Vol. ii., p. 134.) 



The young animal is at first a free swimmer, and then, while still young, enters the 

 plant by some opening in the reproductive capsule ; either by the ordinary one in the 

 male capsule, or by one at the summit of the altered cell. It remains in the cell for the 

 rest of its life, feeding on the colourless plasma of the cell, and laying eggs. 



The body is soft and fusiform, and divided by folds of the cuticle into segments 

 capable of being retracted, one within the other. The head, on its dorsal surface, is 

 prolonged into a projecting proboscis ; and, on the ventral surface, is cut away obliquely, 

 so that the profile tapers to tiie proboscis. The last segment of the body bears two small 

 pointed toes. At the base of the proboscis a flap descends on either side, whose edge is 

 ciliated ; and these cihated flaps surround the entrance to the buccal funnel, at the 

 bottom of which lie the true mouth, and a ciliated organ, capable of protrusion, repre- 

 senting the corona. This organ is excessively mobile, as is also the proboscis, but ig 

 made use of only in a very early stage of the animal's existence. The buccal funnel is 

 long, the trophi virgate ; and the salivary and gastric glands are unusually large. The 

 communication, between these latter and the stomach, is gradually enlarged ; and the 

 gastric glands are ultimately drawn into it. The contractile vesicle is small, and the 



