146 
ME. H. N. MOSELEY ON THE ANATOMY AND 
all the species of Bipalium examined. The ciliated sacs in Nemertines come at once, 
of course, into one’s mind in connexion with these curious structures. Careful exami- 
nation may perhaps give evidence of the existence of similar ciliated sacs in Geoplana 
and other Planarians. Nothing of the kind was found in Rliynchodemus. 
Summary. 
The writer commences by expressing his great obligations to Professor Rolleston, 
whose pupil he formerly was. Professor Rolleston first informed him of the existence 
of Land-Planarians in Ceylon, and of the importance of investigating them. The paper 
was at first intended to be a joint one ; and Professor Rolleston himself made a number 
of preparations of Rliynchodemus , one of which is figured. He likewise rendered great 
aid in the bibliography, and by constant suggestions and assistance during the progress 
of the work. 
Two new species of Land-Planarians from Ceylon are described : — one belonging to the 
genus Bipalium (Stimpson), B. Ceres ; the other to that of Rliynchodemus , R. Thwaitesii , 
so called after Mr. G. H. K. Thwaites, F.R.S., the illustrious curator of the Peradeniya 
Gardens, by whose assistance the specimens made use of were procured. 
Lists are given of all the known species of Bipalium and Rhyncliodemus. 
With regard to the habits of Bipalium , the most interesting facts noted are that these 
animals use a thread of their body-slime for suspension in air, as aquatic Planarians 
were observed to do for their suspension in water by Sir J. Dalyell, and the cellar-slug 
does for its suspension in air. The projection of small portions of the anterior margin 
of the head in the form of tentacles, originally observed by M. Humbert, becomes 
interesting in connexion with the discovery of a row of papillae and ciliated pits in that 
region. The anatomy of the Planarians was studied by means of vertical and longi- 
tudinal sections from hardened specimens. The skin in Bipalium and Rliynchodemus 
closely conforms to the Planarian type, but is more perfectly differentiated histologically 
than in aquatic species, and approaches that of the leech in the distribution, colour, 
and structure of its pigment, and especially in the arrangement of the glandular system. 
The superficial and deep glandular system of the leech are both here represented. In 
B. Ceres peculiar glandular structures exist, which may foreshadow the segmental organs 
of Annelids, it being remembered that these segmental organs are solid in an early stage of 
development. Rod-like bodies (Stabchen-Korperchen) are present in abundance, though, 
• k singularly enough, Max Schultze failed to find any in Geoplana. These Stabchen-Kor- 
perchen are probably homologous with the nail-like bodies of Nemertines ; and it is 
possible that the setae of Annelids are modifications of them. No light is thrown by the 
structure of these bodies in Bipalium on the question whether they are homologous 
with the urticating organs of Coelenterata. 
The muscular arrangement in Bipalium , which is very complex, throws great light 
on the homologies between the muscular layers of Turhellaria and other Vermes. It is 
commonly said that whilst in all other Vermes the external muscular layer is circular, 
