NOTOMMATAD^E. 27 



I first found this species in various waters around London in 1849 ; and have been 

 familiar with it ever since. Wherever filamentous sub-aquatic vegetation grows, it is 

 sure to be abundant. A restless little creature, it ranges among the leaves with 

 incessant activity, now pushing its way through some narrow aperture, using its toes as 

 points of resistance ; now pausing to nibble among the decaying algae ; now scuttling off, 

 by means of its ciliary paddles, to another quarter. The toes, when used as a rest, are 

 often stretched asunder as wide as they will bear. In general a free rover through its 

 tiny ocean, it yet occasionally, though rarely, anchors by the mucous excretion from its 

 toes. 1 These moorings it cannot always loosen when it wishes again to leave port. I 

 have been amused to see one swiftly pursuing its course, dragging after it, at some half 

 dozen times its own length, a bit of floccose sediment attached by an invisible thread. 

 It seemed as it were pursued by an eager persevering enemy through all its windings, 

 which enemy at length proved to be nothing but a bit of inanimate dirt. P.H.G.] 



Length, -5-^ inch ; of toes alone, -j^V^ inch ; of egg, T ^ inch. Habitat. Every- 

 where in still fresh waters of aquatic vegetation : abundant (P.H.G. ; C.T.H.). 



N. COLLABIS (?), Ehrenberg. 



(PL XVI. fig. 6.) 

 Notommata collaris . . . Ehrenberg, Die In/us. 1838, p. 428, Taf. lii. fig. 1. 



SP. CH. Body cylindrical, tapering to both extremities ; ciliated face very long 

 and oblique, projecting far out from the ventral surface just below the mas tax ; head 

 with small everlile auricles; neck large and swollen; nervous ganglion tri-partite, 

 semi-opaque at the free border ; tail distinct ; toes minute. 



This Botiferon (probably Ehrenberg's N. collaris) resembles Copeus Cerberus ; and, 

 like it, might almost be placed either in the genus Copeus or Notommata. I have only 

 seen one specimen, which from its size (two-thirds of that given by Ehrenberg) was, I 

 think, a young one. It can at once be distinguished from Copeus Cerberus by its singular 

 ciliated face (which, on a side view [fig. Ga], gives the head quite a triangular outline), 

 and by its swollen neck. My impression, when I drew fig. 6, was that this swollen 

 condition of the neck was due to the presence of two unusually large and clear gastric 

 glands, which inclosed the mastax between them, on one side, and pushed out the 

 surface of the body on the other. But on referring to Ehrenberg's figure (loc. cit.), I 

 found that he had drawn the gastric glands as small round bodies, decidedly below the 

 neck. Unfortunately I lost my specimen before I had an opportunity of revising my 

 sketch. The front of the head carries two low ciliated projections, one above each 

 auricle ; the auricles themselves are decidedly larger than those of Copeus Cerberus. 



The nervous ganglion consists of three distinct parts : a broad upper portion filling 

 up the head ; a narrower truncate part, projecting downwards to the top of the mastax ; 

 and a long flask-shaped body, the lower end of which, at times, reaches almost to the 

 bottom of the mastax. There is a splendid crimson eye, and a very well developed 

 vascular system. The rest of the internal structure requires no notice. 



It is a sluggish creature, loving to creep among the alg ; but at times it will pro- 

 trude its auricles and swim off into the open, giving one, as it turns, a good view of the 

 peaked gutter, in which the ciliated face projects in front of the mastax, just as in 

 Copeus spicatus and C. labiatus. Although mine was but a young specimen, still it was 

 a handsome Eotiferon ; and a full-grown one of -% inch (Ehr. loc. cit.} would certainly 

 be one of the largest and most striking of the Notommatce. I am indebted to Mr. 

 Thomas Bolton for this rare animal. 



Length. My specimen, ^ inch (Ehrenberg's, ^ inch). Habitat. In water from 

 Button Park (T.B.) : rare. 



1 I once saw half a dozen of these lively creatures, all in a row, attached by their toes to a delicate 

 green filament, and whirling round it like gymnasts on the horizontal bar. C.T.H. 



