108 THE ROTIFERA. 



compressed during the passage, and the parent's cloaca was but little disturbed. This 

 young one extended, before its birth, from the base of its parent's foot to the base of 

 the column ; and, when born, was ^ of an inch long, or about two thirds of its parent's 

 length. 



Length. When extended, about ^ mcn - Habitat. Widely distributed : common. 

 P.H.G.] 



Genus ACTINURUS, Ehrenberg. 



[GEN. CH. The whole animal excessively long and slender ; eyes two, frontal ; teeth 

 two, converging. 



Technically, there is little but its extreme length and tenuity to distinguish this 

 genus from Rotifer; the only difference that Ehrenberg gives (viz. the number of the 

 toes) being founded on error, since all the Eotifers have three, and not, as he assigns to 

 them, two. Yet he has done well to separate the present form. The diminution of 

 thickness, and the great development of length, impart a peculiar fades, which at 

 once precludes the possibility of mistaking it for any species of Rotifer, as soon as seen. 

 Even in contraction the trunk is not sensibly thickened, never swelling in the middle as 

 in the other genera of the family it does. P.H.G.] 



A. NEPTUNIUS, Ehrenberg. 



(PI. X. fig. 6.) 

 Actinurus Neptunius . . . Ehrenberg, Die Infus. 1838, p. 496, Taf. Ixi. fig. 1. 



,, ,, ... Pritchard, Infusoria, 1861, p. 704, pi. xxxv. figs. 481-4. 



... Eckstein, Sieb. u. Kvll. Zeits. Bd. xxxix. 1883, p. 359, 



Taf. xxiv. fig. 17. 



[SP. CH. Frontal column short, carrying the eyes near its base ; corona small ; 

 trunk long, slender, cylindrical ; foot protrusile to twice, the length of the trunk ; spurs 

 small, tu'o-jointed ; toes very long, recurved. 



From its excessive length and tenuity the appearance of the creature is very remark- 

 able. It may be likened to a cylindrical tube out of which protrude a great number of 

 draw tubes from both extremities, principally the posterior one. The head is peculiar, 

 when viewed laterally ; ovate in form, the frontal column very short, and the eyes being 

 oval, dark and large, with the antennal tube projecting obliquely backwards, it presents 

 a ludicrously strong resemblance to the head of a rabbit. The rotatory organs are small 

 and seldom unfolded ; the eyes of an intense red, almost black. The eight or nine joints 

 which constitute the foot are of extreme slenderness, and its spurs consist each of two 

 joints ; the first club-shaped, the second very slender and acute. The three long, slender, 

 cylindrical, diverging toes, are flexible, and commonly bent outward. Owing to the 

 slenderness of the body the viscera are greatly elongated. The mastax is at a consider- 

 able distance from the corona, and is reached by a long buccal funnel. Each ramus 

 bears two inwardly- converging teeth. The digestive canal is apparently undivided, and 

 originates directly from the mastax : with, I think, two small gastric glands. I think I 

 detected a contractile vesicle. The viscera, however, can be demonstrated with difficulty, 

 partly owing to the strong longitudinal corrugations in the dorsal region of the trunk, and 

 partly to the creature's incessant contractions and elongations. The ovary is obvious, 

 and the appearance of the eggs suggests that the animal is viviparous. This singular 

 creature is lively in its motions ; and it is a curious sight to see the immense 

 length of foot suddenly thrust forth from the body, in which it had been completely 

 hidden, the starting out of the horizontal processes, and the diverging of the long toes, 

 as these are successively uncovered. 



Length. Fully extended, - 2 \ 2 inch : closed, 7 \f inch. Habitat. North London ; 

 Leamington ; Caversham : rather rare (P.H.G.). P.H.G.] 



