134 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



In my first revision of the genus Antedon published in 1907 acutiradia was placed 

 in the new genus Thalassometra, and in my revision of the family Thalassometridae 

 published in 1909 it was made the type of the new genus Stiremetra. In my memoir 

 on the crinoids of the Indian Ocean published in 1912 Stiremetra acutiradia was listed 

 and the synonymy and range were given. In a paper on the crinoids of the British 

 Museum published in 1913 I published a short note on one of Carpenter's original 

 specimens which I had examined at the British Museum in the summer of 1910. In 

 my memoir on the unstalked crinoids of the Siboga expedition published in 1918 

 acutiradia was included in the key to the species of the genus Stiremetra and the 

 synonymy and range were given. 



STIREMETRA DECORA, ap. nor. 



PLATE 5, FISURE 18 



Thalassomelra crassicirra (part) A. H. CLARK, Proc. U. S. Nat. Mus., vol. 34, 1908, p. 225 (small 



10-armed spcimen from Albatross station 4107). 

 Cosmiometra crassicirra (part) A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 17; Vid. 



Medd. Naturh. Foren K0benhavn, 1909, p. 186; Crinoids of the Indian Ocean, 1912, p. 215; 



Unstalked crinoida of the Siboga-Exped., 1918, p. 154. 

 Sliremetra decora A. H. CLARK, Bernice P. Bishop Mus. Bull. 195, 1949, p. 74 (nomen nudum. Albatross 



station 4107), p. 110 (station data). 



Diagnostic features. The axillaries are short, nearly or quite twice as broad as 

 long, with a high median carination that may be more or less deeply notched in the 

 middle; the IBri have two long and rather stout blunt spines, one on the distal edge 

 and one near the proximal edge, and a similar but shorter spine on each side; the 

 brachials do not bear dorsal spines; and the cirri, in which the first four segments do 

 not bear dorsal spines, are arranged in 10 definite columns on the centrodorsal. The 

 10 arms are probably about 50 mm. long, and the cirri have 30-40 segments. 



Description. The centrodorsal is conical, about as high as broad at the base with 

 a truncated tip which bears several prominent papillae. The surface of the centrodorsal 

 is not differentiated, the cirrus sockets being arranged hi 10 crowded columns of 2 or 

 3 each. 



The cirri are about XX, with between 30 and 40 segments of which about the fourth 

 is a transition segment. The transition and next following segments are nearly twice 

 as long as broad, and the segments in the outer half of the cirri are about half again as 

 broad as long. The short outer segments bear very high and prominent, rather narrow, 

 curved dorsal spines. 



The ends of the basal rays are visible in the angles of the calyx. 



The radials project slightly beyond the rim of the centrodorsal in the midradial line; 

 their distal border is strongly curved so that they extend well upward in the interradial 

 angles. The distal edge is turned outward and the dorsal surface is curved so that, 

 viewed laterally, the radials are seen to curve outward above the rim of the centrodorsal. 

 In the middle of the dorsal surface of the radials there is a very high transversely 

 broadened oblong or more or less fan-shaped process with a serrate tip. This process, 

 which rises abruptly, is about as high as the middorsal length of the radials. The 

 IBri are about twice as broad as long, somewhat broader proximally than distally, very 

 strongly rounded dorsally, with the proximal and distal borders slightly produced. In 

 the median line they bear two long and rather stout blunt spines, one on the distal edge 



