22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 60 



([3 + 2 + 2 + 3] X5) is fifty. The structure of the division series and 

 of the arm bases is exactly as in S. Unschii; the division series are 

 strongly convex with perfectly straight sides. 



The segments of the enlarged lower pinnules are all short, about 

 as long as broad, of uniform size ; these pinnules are stiffened, though 

 scarcely so much so as those of the species of Stephanometra, and the 

 tip, though sharp, ends in the normal manner. The pinnules are more 

 slender than those of Stephanometra and are evenly tapering. 



This species is most nearly related to that which I recently de- 

 scribed under the name of Seienemetra tenuicirra, which has simi- 

 larly stiffened and enlarged proximal pinnules; but in tenuicirra the 

 pinnules are stouter proximally and more delicate distally so that they 

 taper less regularly, and they are considerably shorter ; and the cirri 

 are very much longer with more numerous segments of which the 

 distal are much longer. 



From the published description and figure I assumed that this form 

 was allied to the species of Stephanometra with which it was asso- 

 ciated by Hartlanb and, as it differed materially from all the forms 

 which I had grouped in that genus, I suggested the generic name 

 Oxymetra for it. Examination of the specimen, however, shows 

 that it has nothing to do with the species of Stephanometra, but is 

 closely related to the species which I have grouped in the genus 

 Seienemetra, especially to S. tenuicirra. 



Now the generic name Oxymetra (Proc. Biol. Soc. Washington, 

 vol. 22, 1909, p. 13) with Antedon erinacea Hartlaub as the type has 

 precedence over the generic name Seienemetra (Proc. U. S. Nat. 

 Mus., vol. 39, 191 1, p. 541) with Antedon Unschii Hartlaub as the 

 type, so that all the species heretofore assigned to the genus Seiene- 

 metra must be transferred to the genus Oxymetra, and the name 

 Seienemetra must be relegated to the synonymy of Oxymetra. 



DICHROMETRA FLAGELLATA (J. Miiller) 



Antedon tlagellata 1891. Hartlaub, Nova Acta Acad. German., vol. 58, No. 

 1, P-73 (1). 



I. Pelew Islands.- — One specimen with about forty arms about 

 140 mm. long; the centrodorsal is large, low hemispherical, 7 mm. in 

 diameter at the base and 3 mm. in diameter at the concave dorsal pole ; 

 the cirrus sockets are arranged in three closely crowded irregular 

 rows ; the cirri are about XL, 27-29, 25 mm. long ; the longer proximal 

 segments are about as long as broad ; dorsal spines, which are rather 

 low and blunt, are developed from the tenth or twelfth onward ; the 



