PART 5 A MONOGRAPH OF THE EXISTING CRINOIDS 527 



and the apex slightly blunted; it is 1.9 mm. in basal diameter and 1.6 mm. in vertical 

 height viewed radially; the cirrus sockets of adjacent radial areas are separated by flat 

 or slightly grooved vertical bands about the width of a socket, whereas the sockets 

 within each area are closer together. The arrangement of the sockets is irregular but 

 there is a tendency towards apically converging columns with 1 to 3 sockets in each, but 

 those on the apical third of the centrodorsal appear to be obsolete. 



The cirri are unknown. 



The radials are produced interradially so that the bases of the division series are 

 separated from one another. 



The axillaries are rhombic with a pronounced but rounded proximal angle, sharp 

 lateral angles and a prolonged distal angle; all the sides are therefore markedly concave. 



Only three smooth brachials of each arm have been preserved. The width at the 

 first syzygy is 1.0 mm. 



Locality. Siboga station 48; Flores Sea (lat. 804'42" S., long. 11844'18" E.); 

 2060 meters; fine gray mud, partially green; April 13, 1899 [A. H. Clark, 1912, 1918] 

 (1, Amsterdam M.). 



PSATHYROMETRA ANOMALA A. H. Clark 



FIGURE 27 



Psathyrometra anomala A. H. CLARK, Notes Leyden Mus., vol. 34, 1912, p. 143 (description; Siboga 

 sta. 211); Die Crinoiden der Antarktis, 1915, p. 116 (range), p. 117 (characters of the centro- 

 dorsal; comparison with Ps. antarctica); Unstalked crinoids of the Siboga-TZxped., 1918, p. viii 

 (discovery by the Siboga and its significance), p. 225 (in key; range), p. 230 (description; sta. 

 211), p. 274 (listed), pi. 26, fig. 90. GISLN, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, vol.5, 

 No. 6, 1922, pp. 139, 140 (comparison with Ps. wireni); Ark. Zool., vol. 15, No. 23, 1923, p. 15; 

 Vid. Medd. Nat. Foren. K0benhavn, vol. 83, 1927, p. 48 (compared with Ps. ivirenf). 



Diagnostic features. The single specimen known has the low conical centrodorsal 

 1.7 mm. in basal diameter and 1.0 mm. in vertical height; the radial areas of the centro- 

 dorsal each have 2 columns of about 2 cirrus sockets and are separated by narrow, 

 irregular, raised interradial areas; the cirri are unknown. 



Description [by A.M.C.]. The centrodorsal is low rounded conical, 1.7 mm. in 

 basal diameter and 1.0 mm. in vertical height. The surface is slightly raised around the 

 cirrus sockets a little more prominently in the interradii. The sockets are arranged in 

 nearly vertical columns, usually two sockets in each of the two columns in each radial 

 area but the upper one may be obsolete. In one radial area there is a small peripheral 

 midradial socket in addition. 



The cirri are unknown. 



The axillaries have a very obtuse proximal angle and a moderately produced 

 distal one, so that only the distal sides are markedly concave. 



The width of the arms at the first syzygy (3+4) is 0.8 mm. and the length from 

 the proximal edge of the IBr[ to the second syzygy (9+10) is 7.0 mm. 



The pinnules have very elongated segments, some of which are expanded at the 

 joints. PI has 10+ segments, possibly about 15; P 2 or P 3 may be the first genital 

 pinnule. Beyond the gonad the segments are very attenuated but tapering. 



Locality Siboga station 211; Banda Sea Gat. 540'42" S., long. 12045'30" E.); 

 1158 meters; coarse gray mud, the superficial layer more fluid and brown; September 

 25, 1899 [A. H. Clark, 1912, 1918] (1, Amsterdam M.). 



