STRETHILL WRIGHT, ON BRITISH PROTOZOA. 219 



covered by Claparede and Lachmann^' differ from any of 

 those at present found on our coast, and I haA^e now to notice 

 two other species of this genus, so remarkable for the peculiar 

 hippocrepian shape of its members and the cells which they 

 inhabit. 



Freya obsteMca. — "Lobes of rotatory apparatus very broad, 

 not folded, the tips bluntly rounded and incurved, so as to 

 resemble the blades of the obstetric forceps. Body fusiform, 

 scarcely longer than the rotatory lobes. Nucleus large, 

 colourless, surrounded by dense, blackish- green pigments. 

 Body and rotatory lobes covered with coarse, longitudinal 

 strise, carrying fringes of cilia. Cell flask-shaped, without 

 a trumpet-shaped mouth. Colour of animal and cell, pale 

 bluish-green.'^ 



Found on oyster shells from deep water in the Firth of Forth. 



Freya sty lifer. — " Rotatory lobes short, narrow, and widely 

 expanded, one of the lobes bearing at its tip a fleshy prolonga- 

 tion or style as long as the lobe. Cell tubular, without 

 trumpet-shaped mouth; cell and animal colourless.'-' 



Freya stylifer is the smallest species I have yet seen of the 

 genus to which it belongs. When contracted within its cell 

 it projects the curious style, probably a sense-organ, beyond 

 the opening, only entirely retracting it when rudely disturbed. 

 The lower part of the cell was not seen. 



Freya producta, T. S. W. (PI. IX). — During the summer 

 of 1861 I had an opportunity of watching this animal as it 

 constructed its remarkable cell. The cell of this species is 

 furnished with an immensely prolonged neck, formed of a 

 ribbon of chitine spirally wound into a tube, cemented by a 

 thick, internal, gelatinous layer, from which it derives its green 

 colour, and covered by a thin layer of that peculiar glutinous 

 secretion which is used by various classes of aquatic animals 

 to attach themselves and their habitations to the sites where 

 they dweU.f The tube thus forms a hollow spring, like the 

 spiral tubes formerly used for conveying gas to moveable 

 burners, and will bend aside like a willow twig on any rude 

 contact from the numerous animals which are constantly 

 dashing about. 



The young Freya producta, which is a free-swimming larva, 

 fixes itself and secretes the lower part or flask of the cell from 

 the surface of its body ; it then begins to build up the neck, 

 by depositing its materials on the upper edge of the con- 



* * Etudes sur les Infusoires et les Khizopodes.' Liv^raisou i, p. 220. 



f I have elsewhere named this substance as it exists on the hard cover- 

 ings of the Hydroid zoophytes " coUetoderm " or " gluing coat," for the 

 secretion itself I propose the term " coUiue." 



