8Q BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



(locality) — Hamann, Bronn's Klassen und Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, 

 p 1579 (listed [in the Tenella group]).— Hartlaub, Mem. Mus. Comp. Zool., vol. 27, No. 4, 

 1912, p. 280 (listed); pp. 394-399 (synonymy; detailed description and discussion); fig. 11, p. 

 397; pi. 7, figs. 1, 2, 5-7; pi. 13, fig. 7, right. 

 Analcidometra armata H. L. Clark, Bull. Lab. Nat. Hist. Univ. Iowa, vol. 7, No. 5 1918 p. 9 

 (Bahamas Exped. station 74).— A. H. Clark, Univ. Iowa Studies Nat. Hist., vol. 9, No. 5, 

 1921 p 8 (obtained by the Barbados-Antigua Exped.), p. 26 (station 11), p. 27 (listed); The 

 Danish Ingolf Exped., vol. 4, No. 5, Crinoidea, 1923, p. 39 (range).— H. L. Clark, Scientific 

 Survey of Porto Rico and the Virgin Islands, vol. 16, pt. 1, 1933, p. 8 (bathymetrical range; 

 quoted from A. H. Clark; West Indies in less than 10 fathoms), p. 9 (in key), p. 12 (occurrence 

 in the West Indies). 



Diagnostic Jeatures.—F I is very stout in the basal portion, so much so as to cause 

 the second brachial to appear as an axillary, and is very much stouter than P;. The 

 short stout cirri composed of segments most of which are about as long as broad, and 

 of which the proximal bear conspicuous transverse ridges, combined with the curiously 

 enlarged Pi, make this little species an easy one to recognize. 



Description.— The centrodorsal is approximately discoidal, thin, and slightly 

 convex. The cirri are arranged in a single marginal row. 



The cirri are XIII-XV, 20 (or somewhat more), from 8 to 10 mm. long in the two 

 larger specimens, short and more or less stout. The short cylindrical segments are of 

 approximately equal length, and of approximately the same form; they are mostly 

 about as long as broad, but may be slightly longer than broad, or slightly broader 

 than long. From the second to the fifth the segments bear on the distal end dorsally 

 a transverse ridge with several small spines; the segments following have a single 

 median spine. The opposing spine is especially stout. 



The radials are visible and are united laterally. The IBri are laterally entirely 

 free, rectangular, always markedly broader than long, in one of the two larger speci- 

 mens with the distal border concave. The IBr2 (axillaries) are more rhombic than 

 hexagonal, as described by Pourtal&s. The two proximal angles of the radials, which 

 are often rounded off, come together m a more or less blunted angle, while the distal 

 border is concave and runs out into acutely pointed anterolateral angles. In the 

 smallest specimen the proximal border of the axiUaries is thickened, imeven, and 

 irregularly and sharply dentate. 



The 10 arms are in the largest specimen about 45 mm. long. The first brachials 

 are short and rather small; they are in contact only at the proximal angles. The 

 second brachials, which are somewhat larger than the first, are often strongly axillary 

 in shape, as a result of having on the outer side an oblique base for the very stout Pi. 

 The first syzygial pair (composed of brachials 3+4) is markedly longer than broad. 

 The four following brachials are approximately oblong with sharp processes on the 

 proximal border. The brachials succeeding pass over quickly through a trapezoidal 

 into a triangular form. The brachials of the middle arm region are longer than broad. 

 In the middle and distal arm region small sharp processes on the distal borders of the 

 brachials overlap the bases of the brachials succeeding. The lateral profiles of the arm 

 as seen in dorsal view are, as a result of the himiplike swelling of the brachials at the 

 insertions of the pinnules, uneven. This is especially noticeable in the middle of the 

 arm, so that the arms at the base often appear more slender than in the middle. All 

 the brachials are smooth. 



The first syzygy is between brachials 3+4. The position of the second syzygy 



