344 PART II. SYSTEMATIC ACCOUNT 



individual and eight in the other. The mesosoma has a ventral furrow. The 

 very slender keels of the bridle are fused both ventrally and dorsally 

 (Fig. ШЛ,В). 



The front part of the trunk has a pronounced ventral sulcus and a broad 

 fringed dorsal ciliated band, beginning at the very front edge of the metasoma. 

 The regular oval metameric papillae are crowded together and each bears a 

 small oval cuticular plaque with a thickened front edge (Fig. 138v4). The 

 succeeding, very long part of the trunk (Fig. 139^4) bears conical or oval 

 papillae, placed chiefly on the sides of the body, more or less at random. The 

 muddy-brown oval plaques on their tips are 35-40/x across (Fig. 139C) and 

 numerous similar plaques are scattered all over the dorsal and ventral 

 surfaces of the trunk. The next, rather prominent part of the trunk, in which 

 are situated the oviducts, is filled with eggs showing through the distended 

 body wall. Papillae and plaques are absent from this region, which, however, is 

 immediately followed by the zone of thickened papillae, where 15-18 very 

 large, conical papillae are irregularly localized on the ventral side (Fig. 

 139D). Each bears on its tip an oval cuticular plaque up to 35/г across. Back- 

 wards from this region the papillae gradually grow smaller and the whole 

 succeeding part of the trunk, as far as the girdles, has small scattered conical 

 papillae. The two girdles, of the usual kind, lie on muscular swellings (Fig. 

 14(M, B). Both are interrupted ventrally and the first dorsally also. The 

 yellowish toothed platelets, 10-14/u. long, are biserial, or in places triserial 

 (Fig. 140C). They are comparatively broad, narrowing towards the hind end. 

 The front group of teeth is well marked, and the part of the platelet occupied 

 by them is colourless and clearly demarcated from the rest (Fig. 140D). A 

 large median papilla with no plaque lies behind the girdles (Fig. 1405). The 

 long slender postannular region of the trunk has metamerically repeated 

 glandular thickenings, each of which bears an almost complete ring of 5-7 

 small conical papillae, with oval plaques 35/x across (Fig. 139£). 



Both the available specimens proved to be females. The body of the larger, 

 whose hind end was torn off, was 15 cm long, of which the postannular 

 region accounted for more than half. The tentacles were not less than 4 mm 

 long, the fore-part of the body 2-3 mm, the protosoma c. 1 mm long, and 

 the trunk c. 0-4 mm broad. 



The firm yellow tube is formed of very irregular muddy-brown rings with 

 clear intervals between them (Fig. 1415). A considerable length at the front, 

 however, is clad externally with a peculiar peripheral layer which is easily 

 stripped off with a sharp scalpel (Fig. 14Ы). This rather thin, brownish 

 layer contains coarse transverse fibres, often branching and interlacing, and 



