166 PROF. F. J. BELL ON BIPALIUM KEWENSE. __ [ Mar. 16, 
3. Note on Bipalium kewense, and the Generic Characters 
of Land-Planarians. By Professor F. Jurrrey Bett, 
M.A., Sec. R.M.S: 
[Received March 16, 1886.] 
(Plate XVIII.) 
In the descriptions given by writers on Land-Planarians especial 
attention is always directed to the form of the head or, as more 
than one author has called it, the tail. This, no doubt, is partly due 
to the fact that in a number of the species the head is often seen to 
have a remarkable hammer-shaped or cheese-knife form, which has 
three times led to the institution of a genus for the reception of such 
species. In other cases, where the worm has been assigned to other 
genera, the head is described as obtusely rounded, or as not sharply 
distinguished from the body. 
Having lately received from Mr. Osbert Salvin, F.R.S., a specimen 
of a Land-Planarian (apparently Bipalium kewense, Moseley), found 
by him among broken fiower-pots in his garden in Sussex, of the 
origin of which nothing definite is known, I have been enabled to 
watch the creature exhibiting its activity. I had not long been study- 
ing it when I noted that the head varied considerably and almost 
constantly in form, so that I thought it well to at once enlist the 
skilful pencil of Mr. C. Berjeau to represent its various appearances. 
Figure A represents the worm, not indeed at its greatest length, 
but in a position which it is apt to assume when in full activity ; the 
head is carried a litile higher than the rest of the body, its edges are 
sharp, its contour convex, and it is well marked off from the rest of 
the body. Figure B, on the other hand, shows the animal in a state 
of torpid quiescence ; the head is now contracted, obtusely pointed, 
only separated by a shallow depression on either side from the sur- 
rounding region of the body. Fig. C shows an intermediate condition 
between A and B. Figs. D-G show various stages in the form of 
the head ’\—hammer-shaped, knob-like, tongue-shaped, or altogether 
irregular. The body may be not more than 2 inches long, when 
the creature looks like a leech or a slug, or it may extend itself to 
6 inches and even more, when it has rather the appearance of a 
thread-worm. In fact, as one looks at it extended on a white dish, 
it calls to mind the Ameba more than any other animal known to 
the zoologist. 
I insist on the variations in the form of the body, and especially 
of the head, because all writers (even those who, like M. Humbert, 
Prof. Moseley, or, the latest of all, Dr. J. C. C. Loman, have had the 
opportunity of examining these forms alive or under natural condi- 
tions) direct, in their descriptions, especial attention to the form of 
the head ; indeed, land-planarians with cheese-cutter or hammer- 
shaped heads (ef. figs. A and D) have been by all naturalists 
’ All the figures are of the natural size. 
