158 PART II. SYSTEMATIC ACCOUNT 



higgledy-piggledy, cheek by jowl with one another (Fig. 895). This part of 

 the trunk is remarkable for the lack of papillae and cuticular plaques, so that 

 there is no trace whatever of the metamerism so characteristic of this region 

 in other Pogonophora. In the male a pair of rounded genital papillae are 

 placed ventrally at the front end of the metasoma (Fig. 89B). The dorsal 

 ciliated organ (Fig. 89Л) is visible as a narrow tract, blunt at its front end and 

 beginning not far from the circular groove dividing the mesosoma from the 

 metasoma. The ventral groove continues for some way along the metasoma 

 and then flattens out, the body becomes more or less cylindrical and the 

 lateral ridges gradually disappear, disintegrating into irregularly spaced 

 glandular regions of rather indefinite form (Fig. 89C). This section of the 

 trunk is of considerable length, making up the greater part of the body, and it 

 is interesting that here, too, adhesive plaques are absent. For detailed study, 

 the zone of thickened papillae was taken from a female (Fig. 89/)). It was 

 found to possess ten large transparent conical papillae, spaced out in a single 

 ventral row. 



There are two closely contiguous girdles, which are broken ventrally, 

 while the foremost is also split on the dorsal side (Fig. 89£, F). The yellowish 

 toothed platelets, 16-23/* long, are arranged in three, or sometimes two, 

 irregular rows (Fig. 89G). Individually they are elongated in form, somewhat 

 narrower at the front end and bear two groups of teeth. The anterior group, 

 directed backwards, is confined to an area approximately one-third the size 

 of the space occupied by the posterior teeth, which are directed forwards 

 (Fig. 89#). Two papillae, devoid of cuticular plaques, lie in the mid-ventral 

 line behind the girdles. The dorsal side of the long postannular part of the 

 trunk is more or less uniform, except for broad glandular regions spaced at 

 rather wide intervals and resembling the dorsal glandular shields of Sibo- 

 glinum (Figs. 14, 112) but more weakly developed. There are no cuticular 

 plaques. 



In one of the individuals studied (a female) the whole body was preserved, 

 except for the tentacles. The overall length of this specimen was 12 cm, 

 almost all of which was taken up by the trunk, the preannular part accounting 

 for about 9 cm and the postannular part for about 3 cm. To judge by other 

 individuals whose tentacles were preserved, these latter would reach about 

 16 mm. The anterior section of the body is 2*8-3-3 mm in length and 0-3- 

 04 mm in breadth. The breadth of the trunk in the anterior region is 0-3- 

 0-5 mm. The ratio of length to breadth of the body is thus approximately 

 400:1. 



The spermatophores (Fig. 91) are greatly elongated spindles, pointed at 



