MEDUS-E. I. 



59 



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 Hartiaub 

 (1905), be designated as dwarf-tentacles. 



(ienus Mitrocoma Haeckel. 



Mitrocoma polydiademata (Romanes). 



Tiaropsis polydiadeiiiata 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- 



dusse. — Journ. Linn. Soc. London. Vol. XII. — p. 525. 

 Tiaropsis " — Romanes 1877, do. (plates). — ibid. Vol. XIII. — p. 194; PL XV, fig. 3. 



Mitrocomclla polydiadevia Haeckel 1879, System der Medusen. — p. 185. 



_ _ Browne 1895, Meduste, L. M. B. C. District. — Proc. Trans. Liverpool Biol. 



Soc. Vol. IX. — p. 279. 



— fitlva Browne 1903, MedusEe from Norway and Spitzbergen. — Bergens Museums Aarbog 



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



— polydiadeniata Browne 1905 a. Medusae, Firth of Clyde. — Proc. R. Soc. Edinb. — p. 767. 



— polydiadcma Browne 1910, National Antarctic E.xped., Nat. Hist. Vol. V. — p. 33. 

 Mitrocoma polydiademata Mayer 1910, Medusae of the World. — p. 290. 



Mitrocoiiiella — Bedot 191 2, Histoire des Hydroi'des, ip'" 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. — 

 H3-droid unknown. 



Haeckel introduced the speWmg polydiade?ua, but Romanes called W. 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 medusae (1876 a) and describes it in the other paper of the same year (1876 b). Romanes 



8* 



