NOTOMMATAD^E. SB 



dark green, very slender, nearly straight, and longer than the Copeus (perhaps C. line- 

 atum}. The animal attacked two of these in succession, taking hold transversely, yet 

 not attempting access there. But feeling its way, it worked, very cleverly, and with 

 manifest intelligence, till its jaws reached the tip. At this, then, they worked eagerly, 

 drawing it in, so that it stretched out lengthwise from the head. No impression, how- 

 ever, was made on the flinty frustule, and it was presently relinquished, to attack 

 another, equally in vain. After some hours, I perceived that it was essaying food 

 again ; and again one of the same long Closteriums, which now was drawn far down 

 the buccal funnel ; while the mastax in its usual position had already eaten a good deal 

 of the desmid, chewing it away, as one would eat a radish. The great auricles (in this 

 very example) were reluctantly and charily put out. They would not be suspected at 

 other times. During several hours' observation I saw them extruded only on one occa- 

 sion, when the creature was gliding through clear water. And then, it thrust out first 

 one and then the other, timidly and tentatively, as it were, and drawing each back 

 before it was nearly out ; then again protruding it ; till, by this time, some impediment 

 was reached, and I saw neither any more. Such was very much my experience of others 

 also. The first specimen that I saw occurred in water sent me, in June, by Dr. Collins 

 from his " happy hunting-ground " at Sandhurst. But more recently Mr. Bolton has 

 sent me examples from the prolific ditch in Sutton Park, near Birmingham, where it 

 revels in company with labiatus arid spicatus. P.H.G.] 



Length, -^ inch. Habitat. Pools and ditches where the larger Diatomacece abound, 

 Sandhurst ; Birmingham (P.H.G.) 



C. CAUDATUS, Collins. 

 (PL XVI. fig. 5.) 



[SP. CH. Form slender, swelling in the middle ; auricles wanting ; one occipital 

 antenna, and one lumbar tentacle ; tail minute. 



In " Science Gossip " for 1872, Dr. Collins described and figured this Notommata of 

 singular facies. I had long desired to examine it, having had my curiosity excited, not 

 only by the brief diagnosis of its discoverer, but by numerous pencilled sketches in his 

 well-filled note-books, committed to me from time to time by his courtesy. At length, 

 by his kindness in sending me samples of water from the original habitat, I have been 

 gratified by the sight of several specimens in healthy activity. It is a species much 

 more abnormal in appearance than in structure : an appearance which depends on the 

 seeming severance of the head from the body by a long interval. The head is large, 

 somewhat square in outline, and, owing to the definition of the brain with its eye, and 

 of the mastax, it catches the observation in a moment. Then follows a neck of unusual 

 length ; and though its thickness is scarcely less than usual, its extreme transparency 

 and colourlessness render it hardly visible till focussed ; and it contains no organs, save 

 on each side the twisted lateral canals, of such filmy mistiness as scarcely to be 

 perceptible when searched for ; and so there seems nothing at all, save the oesophagus, 

 a tube of great subtleness and slenderness running through the middle of its entire 

 length. We seem to see an oval abdomen filled with viscera, and a he^d tied to it at 

 the end of a long string. The head carries at each frontal corner a small globe refractive 

 of light, which I take to be an auricle, though I have not seen them retracted or pro- 

 truded, nor are they manifestly ancillary to speed, being visible uniformly in the animal's 

 twinings and crawlings. The frontal surface between these auricles bears vibratile setse, 

 as well as ordinary locomotive cilia. A large well-developed brain occupies the whole 

 width, and descends, sack-shaped, far down the occiput, bearing on its facial side a bril- 

 liant crimson globular eye, and in its rear, supplying a nerve-thread to the sensitive seta 

 which runs through an antennal tubule, projecting from the back of the head (figs. 5c, d). 

 A mastax of ordinary form in the family has the bent mallei of some thickness. It 

 is figured at 5ft from some very good observations, though, from difficulties inseparable 



