ON A NEW HISTBIOBDELLID. 30*7 



tlie legs ; and from tlie latter point a pair of small bundles 

 run forwards parallel with one another, one on each side of 

 the anus. A small muscle runs along the posterior border of 

 the leg, and another crosses its cavity nearly transversely 

 from the base of the cirrus to the anterior border. 



Digestive System. 



The mouth, a wide, somewhat quadrilateral aperture, is 

 situated, as already stated, close to the anterior extremity of 

 the head. From it a narrow oesophagus (figs. 6 to 8, oes.) 

 leads backwards and slightly upwards through the head to 

 open into the stomach. Below the oesophagus lie the jaws 

 (figs. 1, 4, 5, 7, 8), the anterior extremities of which when 

 they are retracted lie just within the mouth opening, while 

 the posterior ends are at the posterior limits of the head. 



The chitinous pieces of the jaw apparatus (figs. 4 and 5) 

 are arranged in two sets, which, though linked together, are 

 capable of being moved independently to some extent. One 

 of these two sets — the upper jaws — consists of a median 

 piece which I will call the fulcrum, and two sets of lateral 

 pieces composing the rami. The latter set — the lower 

 jaws — is paired throughout. 



The fulcrum of the upper jaws (/.) is a slender, nearly 

 straight rod lying between and somewhat above (dorsal to) the 

 lower jaws. Articulating with its distal end is a small median 

 piece, and with this articulate the right and left rami. 

 The latter consist each of a number of freely articulated 

 basal pieces supporting four teeth. The teeth are provided 

 with hooked claw-like extremities, and their inner surfaces 

 are beset closely with extremely fine transverse ridges, 

 giving them on that aspect the appearance of minute curry- 

 combs. When at rest the fulcrum is drawn back, so that its 

 posterior end is nearly on a level with the posterior ends of 

 the two lower jaws. When it is in this position the rami 

 are folded up into a small compass with the teeth inwards, 

 between and dorsal to the anterior portions of the lower 



