1 2 



My examination of Cc/>/ialodisciis has convinccd me ihat the characters of the coenoeciuin 

 form a reliable mcans of distinguishiny the species in ihat oenus. I am accordingly inclined to 

 think ihat ihe specimen oi Rhabdopleura from Station 204 is prol)ably a new species, characterised 

 l)y the small number of tube-rin^-s, by their comparative delicacy anti thinness, and by their 

 angular ])rojection to the exterior. The specimen is, however, so fragmcntary that 1 do not 

 consider myself justified in ijivino' it a specific name. It may bc hoi)ed that other specimens 

 will hereafter be found among the "Siboga" dredgings which will make it possible to come to 

 a more satisfactory conclusion on this point. There is at present no reason for assuming that 

 the peristomes found have acquired their full number of rings. 



The follovving comparison of the "Siboga" specimen with Norvvegian specimens of A'. 

 nonnani ilh)strates some of the differences between the two forms : — 



Khabdopleida sp. ("Siboga") R. itciniiaiii. 



Number of rings of peristome 13 — 15 5^ — 60 



Length of peristome '64 — 70 mm. 2-59 — 2-88 mm. 



Diameter of peristome 175 — 210 y.. 255 — 270 y.. 



Thickness of wall of peristome, at the middle of a tube-ring. 7'5 — ii'S u. 16 — 24 ;j.. 



Diameter of pectocaulus 20 — 22 y.. 32 rj.. 



It will be observed that the East Indian form is in all respects smaller than the Norwegian 

 form, while the thickness of the wall of its peristome is distinctly less. 



The following .synonymy gives references to some of the more important memoirs dealing 

 with RJiabdopleura. Other papers, not mentioned here, are referred to by Fowler ('92, 2). 



R. uonnaiii All man. 



R. normani AUman, (Quart. J. Alicr. Sci. IX, 1S69, p. 58; Rep. Brit. Ass. (Norwich meeting, 

 1868), 1869, p. 311; HwcKS (80), p. 580, PI. LXXXII, figs. I, 2, 4—7; Lankester {84), 

 p. 622, Pis. XXXVIW^i-— XLI; Fowler (92, i; 92, 2; 04); Norman, Ann. Mag. Nat. Hist. 



(6) XIII, 1894, p. 131; (7) XII, 1903, p. lOI n.; CONTE et VANEY (02, 1,2); SCHEPOÏIEFF (04). 



R. inirabilis Sars (72); Quart. J. Mier. Sci. XIV, 1874, p. 23. 



R. coiupacta Hincks. 



R. compacta Hincks (80), p. 581, PI. LXXII, figs. 8, %a, 9; JULLIEN, Buil. Soc. Zool. France, 

 XV, 1890, p. 183. 



R. griinaldii Jullien. 



R. grimaldii Jullien, Buil. Soc. Zool. France, XV, 1S90, p. 180; JULLIEN et Calvet (03), 

 p. 23, PI. I, figs. \a, \b. 



R. manubialis Jullien. 



R. manubialis Jullien et Calvet (03), p. 24, Pi. I, fig. 2. 



5. mirahilis appeavs to be identical with Spoupcola fistularis, described by F. E. Schulze in 1877, and it has been demonstrated by 

 the observations of S. Lo Bi.^NXu and P. M.A.YER (Zool. Anz., XIII, 1890, p. 687; cf. aho Melly, Rep. Brit. Ass. (Cardiff, 1891), 1892, 

 p. 368) that this is the Scyphistoma form of Nausilhpé. Two other species of Stcphaiwscyphiis are desciibed by Kirktatkick (Ann. Maj;. 

 Nat. Hist. (6), V, p. 13), une of them from the China Sea. Natisithoc is- recorded by M.\AS in his account of the Scyphomediisae coUected 

 by the "Siboga'^-Expedition (Monogr. XI, 1903, p. 19). 



