98 



MEDUSA. I. 



Genus Eutonina Hartlaiib. 



Eutonina indicans Hartlaub. 

 Tiarops indicans Romanes 1876 b. New Species, Varieties, and Monstrous Forms of MedusEe. — Jourii. 



Linn. Soc. London. Zool. Vol. XII. — p. 525. 

 Tiaropsis — Romanes 1877, ibid. — Plate XV, fig. i. 



Thaimiantias sp. Mcintosh 1888. Seventh Annual Report of the Fishery Board of Scotland. — p. 282, 

 PI. 5, figs. 6-9. 

 — - Mcintosh 1890. Ann. Mag. Nat. Hist, Sen 6. Vol. V. — p. 300. 



Eutintalphes indicans Haeckel 1879. System der Medusen. — p. 195. 



— — Hartlaub 1894. Die Coelenteraten Helgolands. — Wissensch. ]\Ieeresnntersuch. 



N. F., Bd. I. - p. 194. 

 Euto)ii)ia — Hartlaub 1897. Die Hydroniedusen Helgolands. — ibid. Bd. II. — p. 507. 



— socialis Hartlaub. Ibid. — p. 506. Taf. XXII, Fig. i, 3, 4, 6, 7; Taf. XX, F'ig. 19, 20. 



Enfi»ii/i»i — Mayer 1910. Medusas of the World. — p. 306. 



Eutonina indicans Bigelow 1913. Medusae and Siphonophorae collected by the "Albatross" in the north- 

 western Pacific 1906. — Proceed. U. S. Nat. Mus. Vol. 44. - p. 34. 



Umbrella somewhat flatter than a hemisphere, 25 — 30 nnn wide; gelatinous substance rather 

 thick. Stomach small, cross-shaped, mounted upon a spindle-shaped peduncle reaching to the level of 

 the bell opening; there are four crenulated lips. 4 radial canals. Gonads linear, wavv, developed upon 

 the lateral sides of the radial canals, leaving a narrow median line on the ventral side free of gonads ; 

 the gonads commence at a short distance from the base of the stomachal peduncle and do not quite 

 reach the circular vessel. There are about 200 short tentacles with conical basal bulbs; no cirri; 8 ad- 

 radial marginal vesicles, each containing about 12 concretions. The velum is narrow. 



Like Bigelow (1913) I prefer the generic nume E/ifonina Hartlaub for this medusa. Bigelow 

 writes as follows: "Mayer uses the name Eiitiniiinn Haeckel for this group (he, however, does not 

 include the number of tentacles as a generic character), but the type species of that genus, E. clephas 

 Haeckel, was beyond question a Eutima. I formerly used the name Eufiinalphcs; but Eutonina seems 

 to have the better claim, because its type species is well known, while that of Eutimalphes, E. prctiosa 

 Haeckel, was founded for a fragmentary specimen which ma}' have been a Tinia. It has never been 

 seen since first recorded". 



With regard to the question of the specific name, it seems to me that Romanes' description 

 of '^Tiarops indicans''' agrees so well with Hartlaub's description of ^'•Eutonina socialis", that there is 

 every probability that they are identical. The high shape of the bell in Romanes' medusa really 

 presents the only noticeable difference and may, as is rightly remarked by Bigelow, very likely be 

 due to contraction. H aeck el's characterisation of "i?////>// ^7//// ^'j indicans" is a quotation of Romanes. 

 The figure of '•^Tliauinantias spy given by Mcintosh is not to be mistaken. 



I. P. van Beneden (1867, p. 87, PL III, figs, i — 6) describes and figures a medusa, "■Geryonopsis 

 Forbesii'\ which is probably identical with Eutonina indicans; true, the gonads are most like those of 



