FLOSCULARIADiE. 57 



that it looks like that of an CEcistes ; at the same instant the setse ' set up a vigorous cilia- 

 like action ; and the animal, case and all, sails slowly, stern foremost, through the water. 

 Two red eyes are very conspicuous in a most unusual position ; namely, near the top 

 of the dorsal lohe. I have seen what I believe to to be the male (PI. III. fig. 2c), but I 

 failed to isolate it so as to make out its internal organs. Its length was about T ? inch. 

 It appeared to have, in addition to the usual ciliary wreath, sette pointing backwards to 

 the foot. 



Mr. T. Bolton discovered F. mutabilis in a pond of Sutton Park, near Birmingham, 

 in May 1884. He described, named and figured it, soon afterwards, in one of the fly- 

 leaves sent out with his specimen tubes. 



Length. About - h '„ inch. Habitat. A pond in Sutton Park, Birmingham (T.B.) : rare. 



F. EDENTATA, CollillS. 



(PL III. fig. i.) 



Floscularia edentata . . . Collins, Science Gossip, Jan. 1872, p. 9, with fig. 



,, ,, ... Hudson, J. Hoy. Micr. Soc. 2 Her. vol. v. 1885, p. 611. 



Corona lobclcss, transversely truncate; setse very short, chiefly on the ventral and 

 dorsal portions of the rim; body larije and stout in proportion to the animal's total 

 length, and nearly as long as the foot. 



Dr. Collins first discovered this ugly Floscule near Sandhurst in 18G7. He says 

 (loc. cit.j that it has no masticating organs, and that the food passes directly into a 

 capacious stomach. As his specimen was a female (for it laid an egg while in captivity) 

 this is very unlikely. My specimens were so gorged with food that no internal organs 

 could be seen, except the stomach and a portion of the ovary. One of them was 

 literally crammed full of specimens of Coeconema, which not only distended the real 

 stomach and the crop, but even protruded above the rim of the coronal cup. How the 

 animal contrived, with its feeble cilia, so to pack itself with these unmanageable diatoms, 

 I cannot imagine. 



Length. My specimens, S J 3 inch ; Dr. Collins', - s \, inch. Habitat. Sandhurst, 

 Berks (Dr. Collins) ; Woolston, Hants (P.H.G.) ; Blair Athol (W. Dingwall) : rare. 



Genus acyclus, Leidy. 



GEN. CH. One dorsal, frontal lobe; setae absent, the coronal cup edged with a 



delicate festooned membrane ; termination o/foot truncate. 



*"ACYCLUS INQUIETUS. LcidtJ. 2 



(PL D. fig. 3.) 

 Acyclus inquictus . . Leidy, Proc. Acad. Nat. Sci. Pa. 1882, p. 213, pi. ii. figs. 1-0. 



The structure of this species has been only imperfectly made out ; but, so far as it has 

 been, the animal appears to be closely allied to the Floscularice ; and so also do the 

 next two species, Apsilus lentiformis , and Apsilus bipera. The characters of Acyclus 

 inquietus given by Prof. Leidy are as follows : — 



" Body fusiform, tapering behind into a long narrow tail-like appendage, by which 

 it is attached, not distinctly aunulated, but becoming transversely wrinkled in con- 



1 It is possible that there may be (as Mr. Bolton says) a row of short cilia round the coronal cup, as 

 well as the larger setae; but my impression is that there is not: I altered my opinion more than once, 

 while watching the creature, but came at last to the conclusion that it swam by means of its seta 1 , and 

 not by a subsidiary row of cilia. 



- Throughout the work the species which are not known to be British will be marked with an 

 asterisk. 



