324 BULLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



FLOROMETRA AUSTINI Sf. nor., A. M. C.' 



FIGURE 16 



Diagnostic features. A species of Florometra with the basal segments of the oral 

 pinnules markedly broadened but not carinate; Pj usually has about 60 segments but 

 the number varies from 45 to 78; it consists of segments which are not longer than 

 broad, the distal ones being shorter and modified with dorsal processes into a distinct 

 comb ; the cirri are L-XCV with up to 59 segments and may be as much as 54 mm. in 

 length, the longest segments about two and a half tunes as long as their proximal widths ; 

 the axillary has a very acute distal angle; the third syzygy is usually at brachials 14 + 15; 

 the size is not known to exceed about 130 mm. arm length. 



Description. Holotype B.M. reg. no. 1958.5.2.1. 



The centrodorsal is rounded conical with a very small dent in the center of the 

 flattened apex. It measures 5.2 mm. in basal diameter by a vertical height (measured 

 radially) of 4.0 mm. The cirrus sockets extend up the sides for more than half the 

 height of the centrodorsal ; they are arranged irregularly, sometimes in distinct vertical 

 columns, or in diagonal columns or in alternating rows. 



Most of the cirri are lost. Their number is estimated from the sockets as about 

 LXXX. The longest peripheral ones have up to 53 segments and measure 45 mm. in 

 length. Those towards the apex of the centrodorsal are progressively shorter, the 

 apical ones having about 36 segments and measuring about 25 mm. In the large cirri 

 the first two segments are broader than long. The third segment is as long as broad and 

 the length increases to a maximum of two and a half times the proximal width (in side 

 view) at about the twelfth segment. From here the length decreases until it is equal 

 to the width at about the thirty-seventh segment (the sixteenth from the tip). The 

 apical segments are very little shorter than broad. In shape the segments are at first 

 slightly waisted but after about the tenth from the base the proximal enlargement of 

 each is reduced so that the dorsal and ventral sides become parallel except for a distal 

 eversion only a little marked on the ventral side but distinctly flared dorsally to be- 

 come a small dorsal spine. On about the last 10 segments this spine disappears. The 

 opposing spine and the terminal claw are both well-developed, sharp and hyaline. 



The segments of the apical cirri are similar but proportionally shorter, the longest 

 being about twice as long as broad. 



The longest remaining arm is of 159 brachials and measures 120 mm. in length 

 probably not more than 10 mm. has been lost. The arms taper more abruptly hi the 

 first third of their length than in the outer two thirds. The breadth at the first syzygy 

 (3+4) is 1.9 mm., at the tenth syzygy (42+43) 35 mm. from the base it is 1.2 mm., and 

 at the twenty-fifth syzygy (105+106) 75 mm. from the base it is 0.9 mm. 



The length from the proximal edge of the IBrj to the second syzygy (9 + 10) is 10.5 

 mm. and to the third syzygy (14 + 15) 15.0 mm. The distal intersyzygial interval 

 is usually three muscular articulations. 



The position of the third syzygy is somewhat irregular; on 6 arms it is between 



*This species has since been collected by the New Zealand Oceanographic Institute at station 

 A. 378 near the Antipodes Islands at 58 meters and by the Victoria University of Wellington at station 

 116 in Cook Strait, between the North and South Islands of New Zealand, at a depth of ca. 550 meters. 

 These records are included in a paper on crinoids from New Zealand waters by A. M. Clark, now 

 (April 1966) going to press; it also contains descriptions of two new species of the subfamily Pero- 

 metrinae, one representing a new genus. 



