126 THE ROTIFERA. 
animal’s form; as it is hard to see how its extravagantly long spines can be of much 
service to it. They evidently forbid its approach to the conferve and floating rubbish 
that are the favourite haunts of its class, under penalty of being probably anchored for 
life to the same spot; and they can scarcely serve as floats, for the animal is a heavy 
swimmer, as if overburdened with these great projections, and is usually found four or 
five feet below the surface. Neither can they be very serviceable as weapons of defence, 
for even the fry of a gudgeon would soon learn to snap it sidewise. At any rate it is a 
most interesting form, and though rare and impatient of captivity it is easily managed in 
the compressorium, as it can be firmly yet lightly held by its long curved spines without 
injury. The lorica is triangular in outline, the dorsal surface convex both lengthwise 
and across, the ventral slightly concave and rather more sharply curved as it approaches 
the hind end. Six spines spring from the anterior edge of the lorica. Two are lateral, 
and are continuations of thickened ridges running part way down the edges where the 
dorsal and ventral surfaces meet. They are equal in size, taper to a point, and curve 
first outward and then upwards and inwards. Then, on either side of the median dorsal 
line is a strikingly unmatched pair. One, the largest of all the six, is stout at the base, 
tapering to a point, and curved first downwards and then upwards, with a graceful 
sweep. The other is an abortive looking spine, of uniform thickness, about one-fifth 
of the length of its partner. In the gap between these two lies the dorsal antenna ; and, 
as this antenna is exactly on the median line, it follows that the longest spine is not in the 
middle of the lorica (as it has been hitherto drawn '), but slightly on one side of it. There 
is yet another pair of spines, of equal length, considerably shorter than the lateral spines, 
and lying one on each side between the dorsal and lateral pairs. The hind end of the 
lorica flows off into yet another tapering spine curving downward and then upward, like 
the longest ; and, with it and the body, presenting on a side view an elegant sigmoid 
curve. At the top of the ventral surface the lorica has a square flap, which can move, 
as on a hinge, to permit the head to come out, and which closes over it, when it is with- 
drawn. There is also a slit, like a trap-door at the hind end of the ventral surface, 
through which the cloaca is emptied. All the front spines are rough, but the hind spine 
is smooth. The corona has a thick dorsal wall crowned with ciliated eminences, and 
surrounding a deep cavity leading to the buccal orifice. This cavity is thrown open on 
the ventral surface by a scalloped V-shaped slit; and is guarded at each side on the top 
by two teat-shaped protuberances armed with stout vibrating styles. All the edge of 
the corona is ciliated, and so are the edges of the ventral slit, at the bottom of which lies 
the buceal orifice: The mastax with its sub-malleate trophi is close to the buccal orifice. 
There is a distinct cesophagus bearing two stalked glands below the mastax, and a cluster 
of rather larger glands just above the stomach. The gastric glands, stomach and intes- 
tine require no notice. A contractile vesicle lies just below the latter, close to the 
cloaca ; the lateral canals and vibratile tags are conspicuous. The muscular system is 
like that of B. rubens (i. p. 8); and it is curious to see how, owing to the flexibility of 
the lorica, the longitudinal muscles can draw together all the frontal spines. As these 
are really continuations of stout chitinous ridges in the lorica itself, the approaching 
spines, with the flexible lorica folding up between them, look exactly like a closing 
umbrella. My specimens died before I had seen the nervous ganglion; but there is a 
dorsal antenna, protruding between the longest and the abortive spine when the head is 
expanded, and pulled in when the head is withdrawn. The adult had a single red eye, 
at the lowest part of the occiput, near the dorsal surface. Mr. Levick says that many 
of the first specimens that he found had two eyes; and that he thinks these animals 
were young ones. It would be very curious should it prove to be the case that two eyes 
in the young approach with age, and coalesce in the adult; especially as Brachiont 
1 Dr. Kellicott, Mr. Levick, and Dr. Imhoff, all place the largest frontal spine exactly on the median 
line of the lorica, and half-way between two small spines; I am satisfied that this is a mistake. Dr. 
Imhoff’s figure shows four small frontal spines besides the three long ones: this also is wrong; there 
are only three, the abortive spine and a pair. 
» «uagall 
os es 
