5J(3 BULLETIN' 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



Ps. congesla); Crinoids of the Indian Ocean, 1912, p. 234 (synonymy; locality); Die Crinolden 

 der Antarktis, 1915, p. 115 (range); Unstalked crinoids of the Siboga-Expcd., 1918, p. 224 

 (in kev; range), p. 22G (synonymy). 

 Psalhyrometra, sp. A. H. Clark, Bull. Mus. Comp. Zool., vol. 51, No. 8, 190S,p.2iO {Albatross sta. 2818) 



Diagnostic features. — The ccntrodorsal is a little shorter than its basal diameter; 

 the cirrus sockets are not in contact with each other and are arranged in 4 columns in 

 each radial area separated by narrow interradial lines; P, has about 13 segments; Pj is 

 shorter with about 9 segments. 



Description. — The ccntrodorsal is truncated conical with somewhat swollen sides, 

 according to the figure measuring 6 mm. across the base and 5 mm. high. The cirrus 

 sockets are deep, about 80 in number, arranged in 4 columns of 4 each. The individual 

 sockets are not in contact. Narrow interradial lines separate the radial areas. 



The cirri are not knowTi. 



Narrow subradial clefts are present, bounded by high interradial bridges. 



The radials are short. The IBr, are short; their dorsal profile stands out at right 

 angles to the dorso ventral axis and forms a right angle with the dorsal profile of the 

 a.xillary, which is parallel to this axis. The IBra (axillaries) are longer than broad with 

 the pro.x-imal angle sharp and much produced and the lateral angles turned distally. 



There are 10 arms. The first brachials are sliort, and shorter dorsally than ven- 

 trally. The second brachials are triangular, bearing the same relation to the first 

 brachials that the axillaries do to the IBr,. The first syzygial pairs (composed of the 

 third and fourth brachials) are moderately short. The next 4 brachials are fairly short 

 and trapezoidal, about half as long on the pinnule-bearing side as on the other. 



P, has about 1.3 segments of which the first is markedly longer than broad and the 

 second is at least 2 mm. long. P^ is small and also has elongated basal segments. P2 is 

 shorter than Pi with 9 segments of which the basal are likewise all elongate. In P3, 

 which is also composed of 9 segments, the 2 basal segments are scarcely longer than 

 broad and those following are also proportionately shorter. 



The disk in the specimen from Albatross station 3404 is 12 mm. in diameter. 



Localities. — Albatross station 3404; between Chatham and Hood Islands, Gala- 

 pagos (lat. 1°03'00" S., long. 89°28'00" W.) ; 704 meters; temperature 6.22° C; rocky 

 bottom; March 28, 1891 [Hartlaub, 1895]. Type locahty. 



Albatross station 2818; east of Santa Cruz Island, Galapagos (lat. 0°29'00" S., 

 long. S9°54'30" W.) ; 716 meters; temperature 6.61° C; white and black sand; April 

 15, 1888 [A. H. Clark, 1908] (arm fragments, U.S.N.M., 36209). 



Albatross station 3358; in the vicinity of Mariato Point, Panama (lat. 6°30'00" N., 

 long. 81°44'00" W.; 1014 meters; temperature 4.56° C; green sand; February 24, 1891 

 [Hartlaub, 1895]. 



The type is not in the M.C.Z., according to Dr. E. Deichmann, to whom thanks 

 are due. 



Geographical range.- — Galapagos Islands and the coast of Panama. 



Bathymetrical range. — ^From 704 to 1014 meters; the average of three records is 

 811 meters. 



Thermal range. — From 4.56° C. to 6.61° C; the average of three records is 5.80° C. 



Remarks. — In his original account (1895) Hartlaub did not say at which of the 

 two localities he gave the specimen described and figured by him was obtained. The 

 only dimension he gives, the diameter of the disk, was taken from the specimen from 



