6 ART. 4. 1. IKEDA : 



group of subdermal glands, situated beneath the skin-body, are 

 seen to open to the exterior by a small common pore (see p) at 

 tlie centre. The papillae are of nearly the same size throughout 

 the whole surface of the body, viz., 0.09-0.06 mm. in diameter. 

 No hook or spine is present. The tentacles are filamentous and 

 tolerably numerous, and are arranged in about 12-14 longitudinal 

 rows around the oral disc, each row consisting of about five 

 tentacles. The rows, in sets of two, are united at the oral end by 

 U-shaped elevations as in the preceding species. Two dark brown 

 eye-spots are present on the ganglion or brain {g, Fig. 29). 



The longitudinal muscles of the body-wall are uniformly 

 distributed. The inner surface of the wall is smooth and shiny 

 like a pearl. There are present two pairs of retractor muscles, 

 of which the ventral pair [vm) originate at about the middle of 

 the body proper close to the nerve-cord {n), while the dorsal pair 

 (dm) arise from a region a short distance behind the anus (a). 

 The œsophagus {oe) is fixed by thin membranaceous muscles and 

 is accompanied dorsally by the dorsal vessel {dv), which pos- 

 teriorly reaches down to the beginning of the intestinal convolution 

 (ic). This vessel develops no contractile villi. The intestinal 

 convolution is made up of 17-23 double spirals and is traversed 

 throughout by the spindle-muscle which at the posterior end is 

 not fixed to the body-wall. There exist in all three fixing muscles, 

 one on the right and two on the left side of the nerve-cord (see 

 fm, Fig. 29). One on each side is attached to the beginning of 

 the rectum, while the unpaired and asymmetrical one on the left 

 side is fixed to the posterior terminal portion of the oesophagus. 

 A large blind rectal gland {rg) is attached to the middle jiart of 

 the rectum. The anterior portion of the rectum is fixed by well 

 developed wing-muscles {tvm). The two segmental organs (so), 



