714 BULLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



vol. 2, 1950, p. 134 (Danish record). — Htman, The invertebrates, vol. 4, Echinodermata, 1955, 

 p. 113 (common in the /njo// collections). 



llathrometra lenella Mohte.vse-^, Danmarfc-E.xpedition til Gr0nland3 NE. kyst, vol. 5, No. 4, Medd. 

 Gr0nland, vol. 45, 1910, p. 243 (carries para.site Myzostoma carpenteri, here recorded from P. 

 prolixa), p. 246 (pentacrinoids compared with those of prolixa). — Grfeg, Sci. Res. Michael Sars 

 1910 Exped., 1921, p. 43 (notes). — KoehlEr, Les ^chiuodermcs des mors d'Europe, vol. 2, 1927, 

 p. 126 (in key), p. 128 (description; distribution). — Djakonov, Les ^chinodermes des mers arc- 

 tiqiies, Leningrad, 1933, p. 25 (range) (in Russian). — Nobre, Echinodermes de Portugal, ed. 2, 

 1938, p. 189 (references; diagnosis). 



llathrometra dcntala Mohtensen, Danmarfc-E.xpedition til Gr0nlands NE. kyst, vol. 5, No. 4, Medd. 

 Gr0nland, vol. 45, 1910, pp. 243, 245.— Grieq, Sci. Res. Michael Sars 1910 Exped., 1921, p. 43 

 (sta. 70; notes), p. 47 (listed). 



llathrometra, sp. A. H. Clark, Fisheries, Ireland, Sci. Invest., 1913, pt. 4, p. 2 (localities); Smith- 

 sonian Misc. Coll., vol. 61, No. 15, 1913, p. 71 (Porevpine stas. 51, 54). 



llathrometra norvegica A. II. Clark, Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 63 (published 

 references to specimens in the British Museum; Triton sta. 5; Trondhjem Fjord, 150-300 fms.; 

 Norway, 800 fms.; Norway; size and number of cirrus segments given; no description) ; Unstalked 

 crinoids of the Siboga-Exped., 1918, p. 246 (referable to Halhromelra). 



Antendon tenella Grieg, Bergens Mus. Aarb., 1913, No. 1, p. 11 (notes). 



llathrometra tenella var. sarsii Gisl£n, Ark. Zool., vol. 15, No. 23, 1923, pp. 7-18, 25-30 (discussion; 

 localities; characters of specimens); Zool. Bidrag Uppsala, vol. 9, 1924, p. 28, footnote, pp. 68, 82 

 (articulations), p. 195 (development of cirri known), p. 205 (centrodorsal in development), p. 

 214 (extent of disk), p. 271 ; fig. 93, p. 87; figs. 114-115, p. 93; figs. 261-268, p. 199.— Morten-sev, 

 Danmarks Fauna, No. 27, 1924, p. 23; Handbook of the echinoderms of the British Isles, 1927, 

 p. 41. — KoEHLER, Les dchinodermes des mers d'Europe, vol. 2, 1927, p. 129. — Mortensev and 

 LiEBERKiND, Die Ticrwclt der Nord- und Ostsee, vol. 12, 1928, p. viii. 86 (food). — Elias da 

 Costa, Chaves dicot6micas para a classificajao dos equinodermes Portugueses. No. 4, Crin6ides, 

 Porto, 1940, pp. 13, 15. — Gisl^n, Lunds Univ. Arsskr., new scr., Avd. 2, vol. 40, No. 8, 1944, 

 p. 80. 



llathrometra sarsi Mortensen, Kungl. Norske Vid. Selsk. Skr., 1923, No. 3, 1924, p. 19 (Trondhjem 

 Fjord). — KoEHLER, Les dchinodermes des mers d'Europe, vol. 1, 1924, p. 60 (depth range). — 

 MoRTE-VSEN and Lieberkind, Die Tierwelt der Nord- und Ostsee, vol. 12, 1928, p. viii 3 (in 

 key), p. viii. 55 (whole North Atlantic), p. viii. 56 (range), fig. 2, 1, p. viii. 3 (cirrus), fig. 90, 

 p. viii. 51 (distribution). — Lieberkind, Zoology of the Faroes, pt. 60, Echinoderma, 1929, p. 2 

 (Faroe references not justified; localities). — Mortensen, Medd. Gr0nland, vol. 79, No. 2, 1932, 

 p. 50 (range). — Torto>jese, Natura, Milano, vol. 24, 1933, p. 163 (depth range). — Djakoxov, 

 Journ. General Biol. Moscow, vol. 6, 1945, p. 131 (immigrant to N. Pacific from Atlantic). — 

 ToRTON'BSE, Bull. Inst. Ocdanogr. Monaco, No. 956, 1949, p. 4 (bathymetrical range). — Htman, 

 The invertebrates, vol. 4, Echinodermata, 1955, p. 113 (common in /njo?/ collections). — Tortox- 

 ESE, Ann. Mus. Civ. Stor. Nat. Genova, vol. 68, 1956, p. 182 (Trondhjem; 80-150 meters). 



Hathrometra tenella norvegica Koehler, Les dchinodermes des mers d'Europe, vol. 2, 1927, p. 129. 



Hathrometrea sarsi Mortensen and Lieberkind, Die Tierwelt der Nord- und Ostsee, vol. 12, 1928, 

 p. viii. 125 (host of parasite). 



llathometra tenella Rivera, Bol. Pesc. Madrid, vol. 14, 1929, p. 50 (in key). 



llarthrometra sarsi Djakonov, Les dchinodermes des mers arctiques (in Russian), Leningrad, 1933, 

 p. 22 (in key), p. 25 (characters; range) ; fig. 12B, p. 25. 



Diagnostic features. — This form seems to differ from //. tenella, of which it repre- 

 sents a northern and northeastern variety, only in being smaller with fewer cirrus 

 segments, which number from 14 to 24, and are usually about 20. 



Hathrometra sarsi lias frequently been confused both with Poliometra prolixa and 

 with Ileliometra glacialis. Some of the records for tliis species can only be explained 

 on the assumption that it has been confused also with species of Trichometra. 



From Poliometra prolixa, which resembles it in color and has Pi similarly elongated, 

 it is at once distinguished by the difference in the arrangement of the cirri on the 



