22 
CHARLES BADHAM. 
only difference being that the nuclei of the ectodermal 
epithelium cells are more numerous, there being always one 
and sometimes two between each bundle of muscle fibrils 
(compare Sukatschoff, fig. 73). 
The proboscis is covered by a thin epithelium, beneath 
which are the longitudinal muscle fibres arranged in similar 
fashion to those of other Ichthyobdellid leeches. A number of 
radial muscle fibres more or less fan-shaped and 15 to 20 in 
one plane (Text-fig. 5, P.) stretch from the periphery of the 
proboscis to the epithelium lining the lumen. They frequently 
surround the longitudinal muscle fibres at their expanded 
ends. Midway between the periphery and the lumen of the 
proboscis are a series of annular muscle fibres. The epithelium 
lining the lumen of the proboscis is well developed. There is 
little difference in the muscular structure of the proboscis 
from that figured by Sukatschoff for Branchellion and by 
Johansson (1896) for Callob della lophii and Abranchus 
brunneus. In the spaces between the radial muscles are 
placed the ducts of the salivary glands and the blood-vessels 
of the proboscis. 
When the proboscis is retracted it lies surrounded by its 
sheath in the anterior lacuna, its apex lying close to the sub- 
cesophageal ganglion. 
The lumen of the proboscis opens posteriorly into a slight 
expansion of the entodermal anterior gut, which has been 
called the bulb in Branchellion. 
The gut narrows immediately and gives off in somite 11a- 
pair of oesophageal glands (Text-fig. 6, (Es . gl.). These lie 
in somites 10, 11, and 12, and communicate with the oesophagus 
by a very narrow lumen (5 to 10 p in diameter) in the eleventh 
somite just above the nerve ganglion. These glands are 
placed dorso-lateral to the accessory male glands and are 
somewhat convoluted. They measure *3 mm. in a longitudinal 
direction, and may, when distended, measure ’1 mm. trans- 
versely. Glands of this nature were first described by 
Johansson (1896) for the Ichthyobdellid leeches Piscicola,. 
Callobdella, and Abranchus. 
