204 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



The 10 arms are perhaps 40 mm. long. The first few brachials are nearly oblong 

 and those following are rather broader than long, somewhat overlapping, and almost 

 triangular, gradually becoming obliquely quadrate. 



The first syzygy is between brachials 3+4, the next usually about brachials 

 12+13 or 13 + 14, and the distal intersyzygial interval is from 4 to 6 muscular articu- 

 lations. 



P! is comparatively small and consists of about 12 squarish segments. P a is 

 usually absent; if present it is similar to Pj but smaller. P 2 is considerably longer 

 and stouter, but the pinnules following are smaller again. 



Sacculi are very abundant on both arms and pinnules. 



The color in alcohol is white. 



The preceding description is adapted from the original description by Carpenter. 

 In Carpenter's figure most of the cirrus segments are shown as nearly or quite as long 

 as broad with a median low transverse ridge. PI is 2.7 mm. long. P 2 is 3 mm. long 

 with 11 or 12 segments. 



Notes. The specimen from Singapore is small with the arms about 20 mm. long. 

 In this small specimen P 2 is composed of longer segments than it is in the fully grown, 

 and P 3 is proportionately shorter. The number of segments in P 2 , however, is the 

 same as in fully grown D. informis, and they have the same overlapping and spinous 

 distal edges. 



The specimen from Sipankot has the arms about 30 mm. long. The cirri are 

 7 mm. long with 14 or 15 segments. P 2 has 10 or 11 segments, the outermost with a 

 small tuft of spines on the distal edge on the side toward the arm tip. 



Localities. Challenger station 208, off Luzon, Philippine Islands (lat. 1137' N., 

 long. 12331' E.), 33 meters, blue mud; January 17, 1875 [P. H. Carpenter, 1888; 

 Hartlaub, 1891; A. H. Clark, 1907, 1909, 1912, 1913] (1, B. M.). 



Albatross station 5249; Gulf of Davao, Philippine Islands; Lanang Point bearing 

 N. 1 mile distant (lat. 706'06" N., long. 12540'08" E.); 42 meters; coral and sand; 

 May 18, 1908 [A. H. Clark, 1909, 1912, 1918] (1, U. S. N. M., 35283). 



Albatross station 5557, in the vicinity of Jolo (Sulu), Philippine Islands; Cabalian 

 Point bearing N. 70 W., 5.2 miles distant (lat. 551'30" N., long. 12101'00" E.); 

 24 meters; sand and coral; September 18, 1909 (2, U. S. N. M., 36022). 



Sipankot, near Sibutu, Sulu (Jolo); 3-6 meters; WUlebrord Snellius, September 

 10-14, 1929 [A. H. Clark, 1936] (1, L. M.). 



Singapore; Prof. Edouard von Martens [A. H. Clark, 1912] (1, Berl. M., 5353). 



Geographical range.' From the Philippine Islands to Singapore. 



Bathymetrical range.- From shallow water down to 42 meters. 



History. This species was described by Dr. P. H. Carpenter in 1888 from a 

 single imperfect specimen that had been dredged by the Challenger at station 208 

 under the name Antedon informis. 



In 1891 Dr. Clemens Hartlaub mentioned the absence of P in Antedon informis 

 in connection with the same feature in his new A. clarae. 



In my first revision of the old genus Antedon published in 1907 I referred informis 

 to my new genus CylLometra, and also listed it under this genus in my revision of the 

 family Himerometridae published on January 9, 1909. In a paper on new crinoids 

 from the Indian Ocean published on April 17, 1909, I compared the arms of this 



