Miscellaneous. 343 



found by tho latter in Cardium rusticum and by himself in C. edule. 

 The elongated flattened body is covered with a delicate membrane, 

 finely striated transversely. At its narrower extremity is an un- 

 armed mouth at the bottom of a sucking-cup. Tho author has 

 observed no oesophageal tube, which is contrary to Lacaze-Duthiers's 

 statement. In the middle region the body shows a closed cylin- 

 drical cavity lined with nucleated cells, and in this part there is also 

 a second circular sucking-disk. The posterior part also has an in- 

 terior cavity, smaller than that in the middle region, with which it 

 has no communication, but having a cord running to an aperture at 

 the base of the caudal lobe (see below). It is probably excretory. 

 Between the anterior and posterior cavities there is a darker, granu- 

 lar, transverse band, from tho lateral extremities of which similar 

 bands are given off anteriorly and posteriorly, the whole representing 

 a capital H. The author regards these as the first traces of genital 

 glands. 



The aboral extremity of the body bears a curious caudal appen- 

 dage, composed of a voluminous median lobe, flattened transversely, 

 and from which are given off on each side two filaments of great 

 length and very contractile, capable of attaining many times tho 

 length of the body and then of retracting by rolling up. 



Although during the months of November, December, January, 

 and February this Bucephalus is to be met with in about 4 per cent, 

 of the examples of Cardium edule, and a certain number of them 

 always in the state above described, which the author regards as the 

 adult Cercarian stage, the Distomum belonging to it could not be 

 found in them ; by the end of March all traces of the parasites 

 disappear*. — Bull. Soc. Linn. Norm. ser. 4, vol. ii. p. 145 (1889), 

 with a plate. 



On the Formation of the Antherozoids in Eudorina elegans. 

 By M. P. A. Dangeaed. 



The colonies of Eudorina elegans are composed of sixteen or thirtv- 

 two cells occupying the surface of a sphere, each possessing two 

 long cilia, a nucleolated nucleus, an amyliferous corpuscle, and a 

 lateral red point ; the colony moves by the agency of the cilia ; 

 asexual reproduction takes place by repeated bipartition of the cells. 



The sexual colonies are male and female, the latter closely 

 resembling the ordinary vegetative colonies, except that the contents 

 of the cells are more opaque and their number may be reduced to 

 four. In the male colonies each cell by successive bipartitions gives 

 origin to thirty-two or sixty-four cells which remain united in the 

 same plane, forming yellowish disks, which escape and move through 

 the water often for a considerable time ; when one of them falls in 

 with a female colony the antherozoids composing it are set free ; 



* In a subsequent note M. Huet records his observations upon another 

 Cercarian parasite of Cardium edule, which he was also unable to trace to 

 maturity. 



