12 THE EOTIFERA. 



time, nor the opportunity, to investigate its structure thoroughly ; but he gave two charac- 

 teristic sketches of the ventral and lateral surfaces, showing the remarkable sucking disc 

 in the foot. According to Dr. Carl Zelinka, who has since found it on the surface of 

 the Channel Synapta, the corona is short, but slightly expanded ; there are ciliated 

 cushions on each side of the buccal aperture, and this latter widens at the top into a 

 projecting beak. The internal structure resembles that of Callidina, except that there 

 is no contractile vesicle. The lateral canals and vibratile tags, though present, are 

 hard to find. The penultimate joint of the foot (figs. 5 a, 5 b) has been altered into a 

 circular sucking disc placed ventrally, and bearing in its centre a circular raised collar 

 or cup, into which the ducts of the foot-glands open. This cup may be considered to be 

 the altered last joint of the foot. There are twelve completely separated gastric glands, 

 arranged in two rows, one above another, round the lower ventral portion of the trunk. 1 

 Length, T } ff to about - r ^ inch (Zelinka) ; ^ n inch (Lankester). Habitat. Parasi- 

 tical on the skin, and in the body-cavity, of Synaptce. 



ADINETA OCULATA, Milne. 

 Callidina oculata Milne (18G). 



SP. CH. Body spindle-shaped ; headsmaW; mastax and rami very small, the latter 

 with two transverse teeth each ; spurs the width of the penultimate joint ; toes three, half 

 the length of the spurs ; eyes two, large, brilliant red. 



Mr. Milne's species is a stouter animal than vaga, and can at once be distinguished 

 from it by its pair of brilliant red eyes. It has also a pair of obvious gastric glands ; 

 whereas in vaga they are either inconspicuous, or absent. 



Length, J^ i nc h t Habitat. Near Glasgow (Milne). 



ASPLANCHNA SiEBOLDii, Leijdig (110), (PI. XXXII. fig. 14). 



Dr. Leydig, who discovered this Asplanchna in 1853, says (loc. cit.) that the female 

 so closely resembles A. Brightwellii, that he should have considered them identical, had 

 it not been for the difference in shape between the males. As Dr. Leydig has observed 

 the male in the ovi-sac, there is no room for suggesting that the jnale of one species 

 might have been accidentally captured among the females of another. 



The male (fig. 14), like that of A. Ebbesbornii, has two cervical humps and two 

 lateral ; but is sharply conical, the corona being the base of the cone, and the extremity 

 of the penis-sheath the apex. Its internal structure is well shown in Dr. Leydig's figure ; 

 and follows so exactly the plan of the male of Ebbesbornii, that further description is 

 unnecessary. Oddly enough, too, the markings on the ephippial egg of Sieboldii resemble 

 those on the ephippial egg of Ebbesbornii, and not of Brightivellii. 



Length. Not recorded. Hatitat. Dirty roadside ditch at Zell (Leydig). 



ASPLANCHNA INTERMEDIA, Hudson (PL XXXII. fig. 15). 



SP. CH. The female indistinguishable from A. Brightwellii: the male with two 

 side humps, but none on the neck ; in other respects closely resembling the male of A. 

 Brightwellii. 



I found this Asplanchna in 1875, and described it, and its male, in the Hon. Mic. J. 

 of that year, p. 52, giving a sketch of the male. Of the female it is not necessary to 

 say more than that Mr. Gosse, who has studied it, agrees with me in saying that he 

 could not distinguish it from Brightwellii. The contractile vesicle and sperm-sac of 



1 Dr. Carl Zelinka's memoir on this parasitic Ilotiferon gives the most minute description of its 

 whole structure, and is accompanied by a profusion of highly interesting figures. The whole memoir 

 deserves attentive study, containing, as it does, not only an exhaustive account of Discopus synaptcc, 

 but also full discussions of many topics concerning the Kotit'era. 



