A MONOGRAPH OF THE EXISTING CRINOIDS 167 



set, and more evenly distributed, gradually giving way to finely serrate longitudinal 

 striations as the ends of the brachials become oblique. 



The base of the animal is moderately compact, the outer edges of the elements of 

 the IBr series and lower brachials being straight and in close apposition. Rather small 

 water pores are present. 



The specimen from Siboga station 286 is slightly smaller and more slender than the 

 preceding, with the spinosity of the IBr series and first two brachials very slightly 

 finer and thicker. The arms are 80 mm. long, and the cirri are 27 mm. long with 44-51 

 segments. 



In the original description I said that this form is nearest Thalassometra attenuata, 

 but it is stouter than that species with shorter and somewhat stouter cirri which usually 

 have fewer segments. It differs markedly, however, in the great development of spines 

 on the division series and arm bases, these parts in Th. attenuata being comparatively 

 smooth. 



Gislen suggested that hirsuta is probably synonymous with gracilis and pubescens. 



Localities. Albatross station 5474; China Sea, in the vicinity of southern Luzon; 

 Malavatuan Island (N.) bearing S. 7330' E., 17.5 miles distant (lat. 1357'30" N., 

 long. 12003'25" E.); 960 meters; bottom temperature 5.1 C.; gray mud and sand; 

 July 16, 1908 [A. H. Clark, 1911, 1912, 1918; Gislen, 1928] (1, U.S.N.M., 35587). 



Albatross station 5275; China Sea in the vicinity of southern Luzon; Malavatuan 

 Island (N.) bearing S. 71 E., 10.75 miles distant (lat. 1355'55" N., long. 12010'15" 

 E.); 214 meters; fine sand; July 16, 1908 [A. H. Clark, 1911, 1912, 1918; Gislen, 1928] 

 (1, U.S.N.M., 35589). 



Albatross station 5445; east coast of Luzon; Atalaya Point, Batag Island, bearing 

 S. 56 E., 5.3 miles distant (lat. 1244'42" N., long. 12459'30" E.); 700 meters; bot- 

 tom temperature 6.8 C.; green mud and sand; June 3, 1909 [A. H. Clark, 1911, 1912, 

 1918; Gislen, 1928] (4, U.S.N.M., 27500 [type], 35588). 



Siboga station 85; Makassar Strait (lat. 036'30" S., long. 11929'30" E.); 724 

 meters; fine gray mud; June 17, 1899 [A. H. Clark, 1918] (7, U.S.N.M., E. 407; Amster- 

 dam Mus.). 



Siboga station 286; Timor Sea (lat. 850'12" S., long. 12702'12" E.); 883 meters; 

 mud, evidently a thin layer; January 19, 1900 [A. H. Clark, 1918] (1, Amsterdam Mus.). 



Geographical range. From the Timor Sea northward to Luzon, Philippine Islands. 



Bathymetrical range. From 214 to 960 meters; the average of 5 records is 696 

 meters. 



Thermal range. From 5.1 to 6.8 C. 



Bottom. Mud, mud and sand, or fine sand. 



History. -Thalassometra hirsuta was described in 1911 from a specimen from 

 Albatross station 5445; at the same time three other specimens were recorded from this 

 station, and one each from stations 5275 and 5474. In my memoir on the crinoids 

 of the Indian Ocean published in 1912 this species was listed and the range and 

 synonymy were given. In my memoir on the recent crinoids of the Siboga expedition 

 published in 1918 seven specimens were recorded from station 85 and one from station 

 286 and notes on these were given. In 1928 Prof. Torsten Gislen suggested that 

 hirsuta might be a synonym of Carpenter's Antedon gracilis. 



