PART 5 A MONOGRAPH OF THE EXISTING CRINOIDS 517 



station 3404. There seems to bo no reason whj' tliis sliould not be considered as the 

 type locality. 



In 1908 I recorded under the heading Psathyrometra, sp., some ann fragments 

 from Albatross station 2818, near station 3404 and at almost the same depth and 

 temperature. There can be no doul)t that these came from a specimen of Hartlaub's 

 species. 



PSATHYROMETRA CONGESTA (A. H. Clark) 



[See vol. 1, pt. 1, fig. 208, p. 241] 



Psalhyrometra congesta A. H. Clark, Proc. U.S. Nat. Mus., vol. 34, 1908, p. 21.3 (in key), p. 221 

 (description; Albatross sta. 3992) ; Notes Leyden Mus., vol. 34, 1912, pp. 141, 142 (compared with 

 Ps. inusitala) ; Crinoids of the Indian Ocean, 1912, p. 235 (synonymy; locality) ; Die Crinolden der 

 Antarktis, 1915, p. 116 (range); l^nstalked crinoids of the Siboga-Exped., 1918, p. 224 (in key; 

 range), p. 228 (references). 



Diagnostic features. — The centrodorsal is about as high as it is broad at the base, 

 with the 20 columns of cirrus sockets closely crowded and not divided into radial groups 

 by naked areas. The cirri and pinnules are unknown. 



Description. — The centrodorsal is conical with the tip rather sharply rounded, 

 5 mm. broad at the base and 5 mm. high; about its sides it bears 20 crowded columns of 

 cirrus sockets, 4 columns of 5 sockets each in every radial area. There is no division 

 of the sides of the centrodorsal into radial areas, though the downward extension of the 

 ends of the basal rays may separate slightly the adjacent sockets. 



The cu'ri are lacking. 



The ends of the basal rays are prominent, forminga dorsoventrally elongate tubercle 

 which at its lower end separates the two topmost cirrus sockets of adjacent radial areas. 

 A deep narrow subradial cleft is present, bridged over interradially by the ends of the 

 basal rays. 



The radials are visible only as small triangles over the upper end of the tubercles 

 representing the ends of the basal rays. The IBri are short with converging lateral 

 borders and with the anterior edge deeply incised by a strong posterior process from the 

 a.Killary. The IBrj (a.xillaries) are rhombic, longer than broad, with the distal angle 

 approximately a right angle, the proxhnal angle acute, and the two proximal sides 

 rather strongly concave. A fairlj- sharp high median keel occupies the proximal two- 

 thirds of the ossicle. 



There are 10 arms, all of which are broken. The first brachials arc sliort, longer 

 exteriorly than interiorly, very sharply incised by an angular proximal prolongation 

 from the second brachials, and interiorly imited for theu- pro.xmial half, their inner sides 

 from the point of union diverging in a straight line which is at riglit angles to their 

 apposed edges. The second brachials are triangular, somewhat longer than broad. 

 The following brachials are at first slightly wedge-shaped, ahnost oblong, broader than 

 long, soon becoming triangular and as long as broad, and wedge-shaped and finally 

 elongate distally. The distal edges of the brachials have a slight spinous projection. 



Syzygies occur between brachials 3-f 4, 9+10, and 14+15, and distally at intervals 

 of 3 muscular articulations. 



Locality. — Albatross station 3992; off Kauai, Hawaiian Islands; Mokuaeae Islet 

 bearing S. 54° E., 3.5 miles distant; 965 metere; temperature 4.22° C; fine grav sand 

 and mud; June 12, 1902 [A. H. Clark, 1908] (1, U.S.N.M., 22684). 



