270 



PART II. SYSTEMATIC ACCOUNT 



ifej 



Fig. A133. Siboglinum inerme: a - part of anterior end of tube; b - middle part of tube; с - girdle 

 region, dorsal view ; d - girdle region, ventral view ; e - spermatophore ; /- toothed platelet. 

 (E. C. Southward). 



The first 1-2 cm of the tube is colourless, wrinkled and limp. The middle 

 2-4 cm has brown, opaque, irregular rings, which vary in length from half to 

 twice the diameter of the tube, separated by colourless interspaces. The 

 posterior part is paler with yellowish rings. Nearly all the tubes are encrusted 

 outside with patches of a brown substance which obscures the interspaces 

 in some places. An apparently complete tube is 50 mm long, while another 

 broken piece of tube reached 65 mm. The diameter is 0-13-0-18 mm. 



The characteristic features of S. inerme appear to be as follows : the presence 

 of a median ventral furrow in front of the bridle, and the gap between the 

 front edge of the mesosoma and the beginning of the dorsal ciliated band. 

 In the occasional development of three adjacent girdles S. inerme is like 

 S. microcephalum. 



Material : more than 20 tubes, many containing animals. 



Locality: the Atlantic Ocean to the southwest of the British Isles and near 

 the west coast of Europe (48°28'N 10°04'W; 47°50'N 7°45'W; 48°54'N 

 10°54'W). 



Depth: 500-1280 m. 



Substratum : mud mixed with stones and shells of Foraminifera.] 



[26. Siboglinum macrobrachium Southward (Fig. В 133) 

 Southward 1961b: 5-7, 21, Fig. 2. 



This species forms part of the Siboga material, originally included in 

 S. weberi. It is probably the subject of Caullery's Figs. 65-70 (Caullery, 1944). 



