238 DISCOVERY REPORTS 



The comparative scarcity of many of these animals, or the inabiUty of the standard 

 collecting gear to secure them, is again brought out. In spite of the lengthy period of 

 the Discovery investigations, several species are represented by only a single specimen. 



ACKNOWLEDGEMENTS 



I am indebted to the Discovery Committee and to Mr C. C. A. Monro of the British 

 Museum of Natural History for the opportunity of studying the material. 



To Professor Dr Sixten Boch I am indebted for the loan of several specimens, named 

 by Theel, for purposes of comparison. 



To Mr R. J. Fant, Zoology Department, the University, Edinburgh, I am indebted 

 for the photographs to illustrate this paper. 



The collection is deposited in the British Museum (Natural History). 



LIST OF THE SPECIES TAKEN 

 The following is the list of the species taken : 



ECHIURIDAE. 



I. Echiurits antarcticus Spengtl. 

 Urechis chiletisis Miiller. 

 Thalassema faex Selenka. 

 Thalassema aiitarcticiiin sp.nov. 



Hamingia arctica Koren and Danielssen. 



2. 



3- 

 4- 



5- 



SiPUNCULIDAE. 



(a) Antarctic. 



6. Phascolosoma amierssoni Theel. 



7. Phascolosoma margaritaceum Sars. 



8. Phascolosoma nordenskjoldi Theel. 



9. Phascolosoma ohlini Theel. 



10. Phascolion strombi (Montagu). 



ib) Eastern Atlantic, etc. 



11. Pelagosphaera aloysii N['mgazzmi. Larval form. 



12. Sipunculiis niidus Linnaeus. 



13. Physcosoma nigrescens Keferstein. 



14. Physcosoma scolops Selenka and de Man. 



15. Aspidosiphon millleri Diesing. 



Priapulidae. 



16. Priapidus caudatus Lamarck var. titherculato-spinosus Baird. 



LIST OF STATIONS WITH THE NAMES OF SPECIES 

 COLLECTED AT EACH 



R.R.S. 'DISCOVERY' 



St. I. 16. xi. 25. Clarence Bay, Ascension Island, 7° 55' 15" S, 14° 25' 00" W. Medium rectan- 

 gular net, 16-27 '^^•> coralline sand and shells. 



Physcosoma nigrescens Keferstein; P. scolops Selenka and de Man. 



