MEDUSJE. I. 



59 



Table VI. Synopsis of the Genera of Mitrocomidce Torrey. 



Strictly spoken, the "cirri" of Cosmetira should not be called with that name, as they are 

 comparatively short and rigid and may not be coiled up spirally; they ought, as stated by Hartlaub 

 (1905), be designated as dwarf-tentacles. 



Genus Mitrocoma Haeckel. 



Mitrocoma polydiademata (Romanes). 



Tiaropsis polydiademata Romanes 1876 a, Prelim. Observations on the Locomotor System of Medusae. 



- Philos. Trans. Roy. Soc. London. Vol. 166. - - p. 274. 



Tiarops Romanes 1876 b, Some New Species, Varieties and Monstrous Forms of Me- 



dusae. - - Journ. Linn. Soc. London. Vol. XII. - - p. 525. 



Tiaropsis Romanes 1877, do. (plates). - - ibid. Vol. XIII. - - p. 194 ; PI. XV, fig. 3. 



Mitrocomella polydiadema Haeckel 1879, System der Medusen. p. 185. 



Browne 1895, Medusae, L. M. B. C. District. - - Proc. Trans. Liverpool Biol. 

 ' Soc. Vol. IX. - - p. 279. 

 f^lh>a Browne 1903, Medusae from Norway and Spitzbergen. Bergens Museums Aarbog 



1903. -- p. 17. PI. I, fig. 3; PI. Ill, figs, i, 3. 



polydiademata Browne 1905 a, Medusae, Firth of Clyde. - - Proc. R. Soc. Edinb. - - p. 767. 

 polydiadema Browne 1910, National Antarctic Exped., Nat. Hist. Vol. V. -- p. 33. 

 Mitrocoma polydiademata Mayer 1910, Medusas of the World. p. 290. 

 Mitrocomella Bedot 1912, Histoire des Hydroi'des, 4 me periode. p. 414. 



Umbrella nearly hemispherical, 12 22 mm wide. Stomach small with a cross-shaped base and 

 4 short, folded lips. Gonads linear or somewhat sinuous, extending along the outer three-fourth of the 

 4 radial canals. About 48 long tentacles with conical basal bulbs; numerous long marginal cirri; 16 

 open marginal vesicles; no ocelli. Manubrium, gonads, and tentacular bulbs red or yellowish-brown. - 

 Hydroid unknown. 



Haeckel introduced the spelling polydiadema, but Romanes called it polydiademata in all 

 of the four papers in which he mentioned the species. 



Romanes mentions this species for the first time in his preparatory work on the locomotor 

 system of the medusas (1876 a) and describes it in the other paper of the same year (1876 b). Romanes 



