A MONOGRAPH OF THE EXISTING CRINOIDS 105 



metra and gave the range of the species. Professor Gislen, after examining the speci- 

 mens of this species in the British Museum, suggested in 1928 that perhaps the proxi- 

 mal syzygies contain muscles, and in 1934 he discussed the brachial structure at length. 



KOEHLERMETRA FLAVA (Koehler) 



[See vol. 1, pt. 2, figs. 210, p. 150, 531, 532, p. 287.] 



Antedon flava KOEHLER, Rev. biol. nord France, vol. 7, 1895, p. 475 (description; Caudan station 4); 

 Ann. Univ. Lyon, Resultats scientifique dc la campagne du Caudan, June 1896, pp. 27, 97 (de- 

 tailed description; station 4), pi. 2, figs. 20, 21. GRIEO, Bergens Mus. Aarbog for 1903, No. 5, 

 1904, p. 35. A. H. CLARK, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 126 (belongs to the 

 genus Thalassometra) ; Proc. U. S. Nat. Mus., vol. 34, 1908, p. 225 (referred to Thalassometra) ; 

 Proc. Biol. Soc. Washington, vol. 22, 1909, p. 18 (not placed in the revision of the Thalassoruetri- 

 dae). HARTLAUB, Mem. Mus. Cornp. Zool., vol. 27, No. 4, 1912, p. 285 (belongs to the Granu- 

 lifera group), p. 285, footnote (close relationship with porrecta). W. DE MORGAN, Journ. Mar. 

 Biol. Assoc., new ser., vol. 9, No. 4, March 1913, pp. 539, 540 (Huxley station 13). MORTENSEN, 

 Handbook of the echinoderms of the British Isles, 1927, p. 25. 



Thalassometra flava A. H. CLARK, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 126 (should be as- 

 signed to Thalassometra); Proc. U. S. Nat. Mus., vol. 34, 1908, p. 225 (same); Amer. Nat., vol. 

 42, No. 500, 1908, p. 542 (characteristic oceanic species); Geogr. Journ., vol. 32, No. 6, 1908, p. 

 603 (same). 



Anlcdon (Crotalometra) flava KOEHLER AND VANEY, Bull. Mus. Hist. Nat. Paris, 1910, No. 1, p. 26 

 (collected by the Travailleur or the Talisman), p. 31 (locality). 



Crotalometra flava A. H. CLARK, Proc. U. S. Nat. Mus., vol. 40, 1911, p. 7 (northwestern coast of 

 Africa), p. 37 (synonymy; south of the Canary Islands, 882 meters; also Bay of Biscay, 1,480 

 [error for 1,410] meters); Unstalked crinoids of the iSiboja-Exped., 1918, p. 148 (in key; range), p. 

 149 (references); The Danish Ingolf-Expcd., vol. 4, No. 5, Crinoidea, 1923, p. 40 (range). 

 MORTENSEN, Handbook of the echinoderms of the British Isles, 1927, p. 25 (localities; in key). 

 KOEHLBR, Echinodermes des mers d'Europe, vol. 2, 1927, p. 133 (habitat). 



Diagnostic features. -The cirri have about 30 segments. 



Description. The centrodorsal is flattened. In one of the specimens it is very 

 large, its diameter reaching 6 mm. In the other it is much smaller with a diameter of 

 only 3 mm. 



The cirri in the latter are XXII, in the former XXVI, with many broken off at 

 the base. They have about 30 segments of which the length increases progressively 

 from the first to the sixth, which is the longest, twice as long as broad; after the tenth 

 the segments become a little broader than long. On the sixth the distal border on the 

 dorsal side begins to rise and forms a point that becomes more marked on the segments 

 following and is continued to the end of the cirri. 



The radials are completely concealed. The IBri are partially concealed and are 

 in close contact laterally. The IBr 2 (axillaries) are entirely free laterally. The IIBr 

 series are 4(3+4). The first two elements of the IIBr series rise on the dorsal side 

 into a well marked blunt tuberosity. 



The 20 very stout arms are flattened laterally. At the proximal angle the lower 

 border of each brachial is produced into a broad_process which accompanies the corre- 

 sponding pinnule. 



Syzygies occur between brachials 2+3, again from between brachials 19 + 20 to 

 between brachials21 + 22, and distally at intervals of from 7 to 13 muscular articulations. 



PD and PI are flattened and prismatic and are composed of 16 or 17 segments of 

 which the proximal are very broad. The two following pinnules are smaller and shorter, 



