202 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



Pa is absent. P, is about 4.5 mm. long, slender, evenly tapering and becoming 

 flagellate in the distal portion, with about 16 segments of which the first 2 are rather 

 over twice as broad as long, the third is nearly as long as broad, and the following 

 increase in length, being about twice as long as broad distally. Pa is 6 mm. long, 

 the largest and longest pinnule on the arm, with about 18 segments of which the 

 first 2 are approximately twice as broad as long, the third is about as long as broad, 

 and the remainder are about half again as long as broad. The pinnule is smooth, 

 the segments being without lateral processes or everted ends. Pa is 3 mm. long, 

 small and weak, nearly as large basally as Pj but tapering more rapidly, with 13 

 segments of which the first is short, the following increase in length to the fourth, 

 which is about as long as broad, and further increase to a length of about twice the 

 breadth in the terminal portion. The following pinnules are similar, soon becoming 

 more slender and gradually increasing in length. The distal pinnules are very slender 

 and hairhke, about 7 mm. long with 23 segments of which the first is short and cres- 

 centic, the second is nearly as long as broad, slightly less in width distally than proxi- 

 mally, the third is squarish, and the remainder are about half again as long as broad, 

 becoming about twice as long as broad in the distal portion. 



The color in alcohol is brownish purple with the cirri and the dorsal sinface 

 lighter. 



Locality. — Oazelle; Dirk Hartog Island, Western Australia; 13 meters [A. H. 

 Clark, 1909, 1911, 1912, 1915, 1916, 1918; Hartmeyer, 1916] (1, Berl. M., 6381). 



History.— This species was originally described by me on March 10, 1909, under 

 the name Oligometra studeri from a single specimen in the Berlin Museum (Cat. No. 

 2964 [part]) that had been collected by the Gazelle at Dirk Hartog Island, Western 

 Australia, in 7 fathoms. I said that this new form is readily distinguishable from 

 the ten previously described species of the genus [Oligometra]; the elongate Pi of 

 0. bidens, as well as the two dorsal processes on its cirrus segments, the very numerous 

 cirrus segments of 0. gracilicirra, the short stout chrus segments of 0. pinniformis, 

 the single dorsal spine on the few stout cirrus segments of 0. caribbea, the strong 

 imbrication of the brachials of 0. imbricata, and the spines or lateral processes on 

 the proximal pinnules of 0. gracilicirra, 0. carpenieri, 0. japonica, 0. pulchella, and 

 0. serripinna separate them at once. The elongate proximal pinnules described in 

 0. adeonae would serve to differentiate it, if adeonae should be shown to really belong 

 to the genus Oligometra. Oligometra studeri is most closely related to the group of 

 species typified by 0. serripinna. 



On April 17, 1909, I wrote that by an unfortunate slip I had described a new 

 comatulid from Dirk Hartog Island under the name Oligometra studeri, whereas it 

 belongs in reality to the genus Cyllometra and should have been called Cyllometra 

 studeri. Cyllome'ra studeri is related to C. informis which was taken by the Challenger 

 among the Philippine Islands in 18 fathoms. Cyllometra studeri differs from C. 

 informis most obviously in its smooth pinnules, the lower and middle pumules in the 

 latter having slightly overlapping and spinous ends to the segments, and in the much 

 greater length and greater slenderness of Pj, which is twice as long as P3 and is com- 

 posed of 18 segments most of which are elongated, instead of only slightly when at 

 all longer than P3 with 12 segments most of which are about as long as broad. Both 



