I9I5.] E. GHosu: The Anatomy of a Burmese Slug. 159 
The pental sheath consists of two portions: (1) A stout 
reniform mass containing the penis when the latter is fully 
retracted, the wall of the penis being continuous with that of 
the penial sheath at their distal ends. (2) A narrow tubular 
portion, which ends in the external aperture .with the right 
stmrothian gland. 
(v) The vight simrothian gland consists of two portions: 
(r) A narrow tubular portion coiled in various ways in its distal 
two-thirds. (2) A stout portion (also looped once) ending in the 
external aperture. At the junction of the two, is a fine tubular 
blind-sac (coecum) directed towards the outer end. ‘The base of 
the sac gives attachment to a few muscle fibres. ‘These corre- 
spond to the first and fourth portions of the simrothian glands of 
A. (P.) sanguinolenta. 
V. Nervous System. 
The general arrangement of the ganglia is similar to that in 
other species. As the system has not vet been studied in detail in 
other species, it is convenient to deal with them rather fully 
in the present species. 
(i) Cerebral ganglia. Each ganglion contains numerous 
groups of ganglionic cells arranged correspondingly tothe origin of 
nerves from it. Three such rows can be recognized as follows :— 
(1) An elongated row of cell-group in the inner third of the 
ganglion along the whole length. 
(2) A similar row in the outer third. 
(3) A narrow elongated group in the middle third in its 
anterior fourth. 
The nerves (C 1-5) from the cerebral ganglion :-— 
(1) A stout nerve on the inner side lying close to the nerve 
of the opposite side. It arises from the ventral 
aspect and supplies the ommatophore. 
(2) A stout nerve dividing into three branches immediately 
after its origin. These supply the cephalic flap and 
its retractor muscle. One of these communicate 
with the buccal ganglion of the same side. 
(3) A stout nerve from the antero-external corner of the 
ganglion ; it supplies the outer side of the head. 
(4) A fine nerve on the dorsal aspect of the nerve (3) 
supplying the dorsal integument of the head. 
(5) Several small nerves on the outerside supplying the sides 
of the head and the muscular strands in connection 
with the proboscis and proboscis-sheath. 
(6) A few fine nerves from the ventral aspect to the body wall 
at the base of the proboscis, one of which supplies 
the retractor muscle of the tentacle (C 6). 
(ii) Buccal ganglia.—Kach ganglion gives off (1) a number of 
nerves which spread over the proboscis and its radular portion ; 
(2) one long nerve which passes along the oesophagus and serves 
