170 



G.L.J. PATERSON AND A.G. GLOVER 



individuals were between 0.75 to 4.5 mm long (Fig. 5). The relation- 

 ship between length of specimen and number of chaetigers is given 

 in Fig. 4. The graph indicates that initially as individuals increase in 

 length so the numbers of chaetigers increases linearly, however, at 

 the upper size there is wide variation in numbers of chaetigers, 

 suggesting that there may be an upper limit to chaetiger number. 



Growth in Sigambra grubii Muller, 1858 also appears to show a 

 linear relationship between length and number of chaetigers over a 

 similar size range as S. magnuncus (Salazar-Vallejo, 1990). How- 

 ever, there was more variation in the relationship between size and 

 the chaetiger on which the first hook appeared. 



Acknowledgements. We would like to thank Dr Andrew Mackie (Nat- 

 ional Museum of Wales) and Alex Muir (NHM ) for reviewing the manuscript. 

 The assistance of the Electron Microscope and Mineral Analysis Division in 

 the preparation of specimens for the SEM is gratefully acknowledged. The 

 specimens were collected during a number of oceanographic expeditions and 

 the authors would like to thank the officers, crew and scientific parties of 

 Discovery 185, 186, 194,206 and Challenger 79. 1 1 1 .We would also like to 

 thank Dr John Gage, Peter Lamont (Scottish Association for Marine Science), 

 Dr Brian Bett (Southampton Oceanographic Centre) and Joel Galleron 

 (CENTOB) for making material available to us. This work was partly 

 supported by a contract from EU Marine Science and Technology programme 

 Contract No MAS2-CT920033, which is gratefully acknowledged. 



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