174 PART II. SYSTEMATIC ACCOUNT 



crossed by irregular transverse light stripes (Fig. 95B). The diameter of the 

 tube reaches 1-05 mm, the length of the greatest fragment 15 cm. 



Material: 10 incomplete specimens and a number of torn-off tubes. 



Locality: the western part of the Bering Sea at depths of 3260-3857 m. 



П. Family Siboglinidae Caullery, 1914 



[The recent discovery of the genera Nereilinum and Siboglinoides has 

 necessitated revision of the diagnosis of the Siboglinidae. The original 

 disgnosis given in the Russian edition of this book has been replaced by a 

 revised version. 



The Siboglinidae are Athecanephria with the number of tentacles reduced 

 to two or only one. There are never more than two rows of pinnules on each 

 tentacle and they may be reduced to only one row or be absent altogether. 

 The anterior part of the preannular region of the trunk bears well-developed 

 adhesive papillae, without cuticular plaques, arranged in a metameric fashion. 

 The tube is flexible, ringed, sometimes also segmented. There are two 

 genera - Siboglinum and Siboglinoides. 



Type of the family : Siboglinum Caullery.] 



1. Genus Siboglinum Caullery, 1914 



Caullery, 1914: 2014; Caullery, 1944: 1-26; Caullery, 1948: 495-9; Dawydoff, 1948: 

 141-63; Beklemishev, 1951: 267-9; Ivanov, 1951: 739^12; Beklemishev, 1952: 295-8; 

 Ivanov, 1952: 372, 374, 389, 390; Ushakov, 1953: 179; Dogiel, 1954: 250; Hartman, 

 1954: 184, 185; Ivanov, 1954a: 100; Ivanov, 1954b: 69, 79; Zenkevitch, Birstein and 

 Belyaev, 1954: 66, 68; Abrikosov, et al. 1955: 472; Ivanov, 1955a: 177; Ivanov, 1955b: 

 382; Ivanov, 1955d: 175; Ivanov, 1955e: 223; Giinter, 1956: 187; Ivanov, 1956b: 1863, 

 1864, 1867, 1870; Ivanov, 1956c: 165, 166, 168; Jagersten, 1956: 211-252; Kirkegaard, 

 1956a, 79, 82; Kirkegaard, 1956b: 186; Abrikosov, 1957: 232, 233-6, 238, 239; Alvarado, 

 1957a: 553; Beklemishev, 1957: 397; Ivanov, 1957a: 431, 433, 434, 439, 440-61, 490-7; 

 Ivanov, 1957b: 112744; Obut, 1957: 13; Borradaile, et al. 1958: 714-16; Dajoz, 1958: 

 225-7, 229, 231-5, 237, 238; Ivanov, 1958a: 1363, 1369, 1371; Ivanov, 1958b: 1682, 1688- 

 90; Ivanov, 1958c, 1 ; Ivanov, 1958d: 1-2; Ivanov, 1958e: 1070-86; Jagersten, 1958: 367; 

 Kirkegaard, 1958: 1086, 1087; Manton, 1958: 748, 751; Marcus, 1958: 49; Southward, 

 A. J. and Southward, E. C, 1958a: 1607; Southward, E. С and Southward, A. J., 1958b: 

 627-32; Vinogradova, 1958: 112; Ivanov, 1960a: 1530, 1531, 1533, 1534, 1535, 1537, 1538, 

 1539, 1541, 1543, 1552, 1567, 1570, 1572, 1573, 1574, 1580, 1583, 1588, 1590, 1592, 1593, 

 1597, 1604, 1605, 1606, 1607, 1609, 1610, 1611, 1614, 1616, 1620, 2165; Ivanov, 1960b: 

 7-9, 12, 14-16, 18, 19, 23, 24, 27, 28, 47, 54, 57, 59-61, 63, 66, 69, 75, 76, 78, 79, 82, 87- 

 96, 97, 98, 102, 105-110, 114, 124, 162, 183, 215, 219. 



The protosoma is divided from the mesosoma by a more or less distinct 

 groove, which may be simple or curved backwards on the dorsal side. The 



