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PART II. SYSTEMATIC ACCOUNT 



undoubtedly the first papilla of the zone of thickened papillae. The plaque 

 has approximately the same width as the others but is much shorter — not 

 more than 30/* long. The dark front border is similar to that of some plaques 

 of the nonmetameric region of the trunk, but considerably narrower (Fig. 

 D162Z)). 



1 



Fig. D162. Galathealinum brachiosum: cuticular plaques. 



A - from the metameric section of the preannular region; B,C- from the non-metameric section. 



D - from the zone of thickened papillae. (After Ivanov 1961c.) 



Our specimen proved to be a female. The various parts of the body had 

 the following dimensions: length of tentacles, 18 mm; length of protosoma, 

 1-5 mm; length of mesosoma, 4-5 mm; length of metameric part of the 

 metasoma, 27 mm; length of the rest of the trunk as far as the zone of 

 thickened papillae, 115 mm; breadth of mesosoma 1-5 mm. Galathealinum 

 brachiosum appears to be one of the very longest species amongst the Pogono- 

 phora. The greatest length so far recorded is 36 cm in Zenkevitchiana 

 longissima. 



The tube is very like that of G. bruuni. For almost its whole length it 

 consists of short segments whose length is for the most part equal to the 

 diameter of the tube. The front edge of each segment is drawn out into a 

 narrow funnel-like frill (Fig. El 62). The tube is a dark earthy brown, almost 

 black. The surface is thrown into small creases and is somewhat glistening. 

 The funnels are soft and pliant; they consist entirely of the external fibrous 

 layer of the tube (Fig. F 162,4), which is more strongly developed than in 

 G. bruuni. The fibres of this layer are thicker too, reaching 7-12/x, while in 

 G. bruuni they are only 2-4/x in diameter. 



