110 
ME. H. N. MOSELEY ON THE ANATOMY AND 
the animal’s length of at least the width of the central one, from which they differ by 
being of a slightly browner yellow colour. The whole of the animal’s dorsal aspect is 
irregularly dotted with black specks. The semicircular anterior border of the head is 
limited by a dark violet line, immediately anterior to which a broader but similarly 
semilunar band of flesh-colour is to be seen on the dorsal surface. The central dorsal 
band is in some specimens prolonged up so as to join this band ; in others it falls short 
of this ; in all it swells out into a sort of lozenge-shaped termination, sharply defined 
on each side by a dark violet patch, which shades off gradually into the dusky yellow of 
the lateral bands of the body. On the under surface of the body, on each side where 
the convex surface of the dorsal aspect meets the nearly flat ambulacral surface, a slight 
ridge is formed extending the whole length of the body. This ridge is highly charac- 
teristic of this species, and contains peculiar glandular bodies not present in the other 
two species of Bipalium examined. 
Dimensions of an average specimen after contraction in spirit : — 
millims. 
From anterior extremity to mouth 52 
From mouth to generative orifice 12 
From generative orifice to posterior extremity . . . .15 
Entire length ... 79 
Habitat. The Eoyal Botanic Gardens, Peradeniya, Ceylon, in company with B. Pro- 
serpina and B. Diana. 
The possession of a large series of specimens allowed the difference between young 
animals and adults to be studied. In Bipalium Ceres and also B. Diana the very young 
specimens are much more definitely marked than the adults. The animals gradually 
lose their definite striping as they grow older. The case is paralleled in many instances 
amongst higher animals. It would appear here as if the species were endeavouring to 
escape detection by enemies by getting rid of a somewhat conspicuous colouring which 
at present survives only in the young condition. 
Fig. 2, Plate X., represents a very young specimen of B. Ceres. The lateral bands are 
in young specimens much browner, and the central band of a brighter yellow ; the two 
linear intermediate stripes are jet-black. 
Fig. 3, Plate X., shows a very young specimen of B. Diana. A comparison of this 
drawing only with that of M. Humbert’s of the entire animal would lead to the conclusion 
that the present must belong to another species, but the examination of a large series of 
specimens has shown that this is undoubtedly the young of B. Diana. A very narrow 
light-coloured line is seen in the midst of the broad black line on the head, and this 
light-coloured line extends a short distance along the animal’s back ; it represents the 
broad median light-coloured line of B. Ceres , and shows B. Diana to be five-striped in 
the early condition, as are nearly all the Ceylon Land-Planarians. The longest specimen 
of B. Diana obtained measured 5^ inches in length and \ inch in breadth ; it was used for 
