430 PART II. SYSTEMATIC ACCOUNT 



observed. The tentacles themselves are four to five times as long as the fore- 

 part of the body, and at their base, in the mid-ventral line, may be noticed an 

 aperture which places the intertentacular cavity into communication with 

 the exterior (Fig. 167 A). The metameric part of the preannular region of the 

 trunk, like the fore-part of the body, is somewhat compressed dorso-ventrally. 

 The broad ventral sulcus (Fig. 167 A), which has a smooth surface along the 

 bottom, runs between pronounced lateral ridges which bear the adhesive 

 papillae. The latter are rounded projections, touching one another in front 

 but more widely separated farther back (Fig. 166). On each papilla lies a 

 small heart-shaped pulvillus whose narrow end points backwards and which 

 bears in its turn an adhesive plaque (Fig. ZAA). In the fore-part of the trunk 

 these are similar to those of L. zachsi (p. 423), but distinguished from them 

 mainly by the slightly larger size of the horseshoe, which is 70/x across and 

 black in colour. Towards the hind end of the metameric region they become 

 simpler and semi-lunar in shape. Attentive observation reveals that at the 

 same time the pulvilli also become simpler in shape and more or less rounded 

 in outline. The simple, semi-lunar plaques are smaller than the horseshoes. 

 The metamerism of the adhesive papillae of the front part of the trunk is far 

 from complete, as may be seen in Figs. 166 and 167^4, and subject to great 

 individual variation. The number of papillae in this region varies from 47-60 

 pairs of which the anterior 22-30 pairs bear horseshoe plaques. The large 

 rounded genital papillae of the males lie at the front end of the trunk (Fig. 

 161 A, C). The dorsal ciliated band is well developed, beginning straight 

 away at the intersegmental groove and stretching back along the greater part 

 of the metameric region (Figs. 166, 167 B). The non-metameric part of the 

 preannular region of the trunk is very long and characterized by the absence 

 of any ventral sulcus and by the irregular scattering of numerous adhesive 

 papillae, lacking pulvilli, along the ventral surface. The cuticular plaques in 

 this region are simple hoops 60^ across (Fig. 345). A little in front of the 

 girdles is a weakly marked zone of thickened ventral papillae, represented by 

 five to ten rounded, scattered papillae. The broad girdles lie on muscular 

 ridges which are sometimes flattened out and imperceptible. Both the girdles 

 are interrupted dorsally and ventrally, but in a single individual the second 

 girdle had no dorsal break, while the first girdle had a broad dorsal gap. 



Fig. 167. Lamellisabella johanssoni: A - front end of a male from the ventral, В - from the dorsal, 

 and, С - from the left side ; D - region of the girdles in ventral, and, E - in dorsal view ; F -part 

 of a girdle; G - toothed platelet; H - hind end of the body. 





