FROM THE AUTHOR'S PREFACE TO THE 

 RUSSIAN EDITION 



The Pogonophora form a group of invertebrates of high systematic rank in 

 whose structure some of the essential features of the primitive Deutero- 

 stomata have been preserved. An understanding of their organization will bring 

 us nearer to the construction of an overall scheme of systematic classification 

 of the animal kingdom and help elucidate the phylogeny of the Deutero- 

 stomata. The secondary or false metamerism which is just beginning to 

 develop in pogonophores helps us to understand the metameric structure of 

 the Enteropneusta and the origin of the segmental structure in the Acraniata 

 and Vertebrata. And the Pogonophora are interesting from the physiological 

 point of view, as Metazoa which lack a gut and feed exclusively by means of 

 tentacles. 



Forty-five years have passed since the first report of a pogonophore 

 (Caullery, 1914). Even eight years ago [i.e. early 1952] only three species 

 were known, their organization remained almost unknown and their sys- 

 tematic position was obscure. Since then, however, there has been a consider- 

 able increase in pogonophoran material, chiefly owing to the various cruises 

 of R. V. Vityaz' sent out by the Institute of Oceanology of the Academy of 

 Sciences of the U.S.S.R. 



The lively interest shown by wide circles of zoologists and the lack of 

 publications giving any details of the morphology and systematics of Pogono- 

 phora have stimulated me to undertake the composition of this work. In the 

 first part I have, to the extent permitted by our present state of knowledge, 

 summarized the morphology, embryology, ecology, classification and other 

 general questions. An abridged version of this part has already appeared in 

 French (Ivanov, 1960a). In the systematic part of the work I have given 

 descriptions and diagnoses of all the forms known at present. Some features 

 of species which have been described earlier are given more accurately and 

 in greater detail. In particular, my earlier reports on the morphology of the 

 girdles, toothed platelets and tubes (Ivanov, 1952, 1957a) have been checked 

 upon new material, corrected and supplemented. 



Many questions on the morphology, physiology, embryology, ecology, 

 systematics and geographical distribution of the Pogonophora are still far 

 from clear or have not even been touched upon, and we are far from drawing 



