MEDUS.^. I. 7 



species are given in my paper on the Anthomednsse and Leptomedusce of the "Michael Sars"). Now 

 it is not difficult to fancy a transition from the facts as established in these species to the t\pe of 

 gastrogenital organs found in most Laodiceidcr. If the gonads disappear in the interradial parts, we 

 have, on each side of the radial canals so far as these are connected with the edges of the stomach, 

 a series of gonadial folds, forming together a continuous, folded band along the part of the canal 

 concerned. An outward displacing (towards the bell-margin) of these gonads will have the effect, that the 

 proximal ends are somewhat withdrawn from the centre of the umbrella, while the distal ends, being 

 removed outwards, will drag along with them the adjacent parts of the wall of the stomach, forming a 

 funnel-shaped extension of the stomach along the lower side of each of the radial canals. Then we have 

 the type, which is found in Pfychogcna and Laodicea (see below). The modification of this type within 

 the different forms, here dealt with, will be mentioned below under the descriptions of the species. 



The emancipation of the gonads from the stomach is not so far advanced in the Laodiceida 

 (the species here described) as in the other Leptomedusse; this indicates a lower systematical position 

 nearer to the Anthomedusse. In Laodicea, Ptychogena and Stauropliora the gonads are developed in 

 folds of the lateral walls of the radial canals; in the case of the two first mentioned genera the 

 proximal parts of the gonads are frequently developed in the walls of the stomach along both sides 

 of the lines (the cross-shaped figure) by which the stomach is attached to the subumbrella. In Stauro- 

 pliora the structure of the gastrogenital organs is secondarily complicated (see below). In Chro- 

 viatonema the gonads do not form continuous bands, but consist of a row of sack-shaped invaginations 

 on each side of the radial canals; some of the proximal gonadial sacks are situated within the corners 

 of the stomach in the dorsal walls of the latter along the arms of the cross-shaped figure. These gonadial 

 sacks, with their narrow, split-shaped openings, recall the gonadial sacks, arranged in rows, in Calycopsis. 



Genus Chromatonema Fewkes. 

 Chromatonema rubrum Fewkes. 



Plate I, figs. 1—8, 



Ckromatoiu-ma rubruiu Fewkes 1882. Acalephae, East Coast of New England. — Bull. Mus. Comp. Zool. 



Vol. 9. No. 8, p. 305. PI. I, fig. 41. 

 ThauiiHiiitias — Mayer 1910. Medusse of the World. Vol. I, p. 199. 



— — Kramp 1913. Medusse, "Tjalfe"-Exp. — Vidensk. Meddel. Dansk naturh. Foren. 



Bd. 65, p. 267. 



— — Kramp 1914. Medu.ser og Siphonophorer. — Conspectus Faunae Groenlandica;, 



p. 419. 



1 PtycJtogena erythrogonon Bigelow 1909. Medusae, Eastern Tropical Pacific. — Mem. Mus. Comp. Zool. 



Vol. 37, p. 150. PI. 5, fig. I. PI. 38, figs. 8, 9. PI. 39, figs. 1—7. 

 ? — Herhvigi Vanhoffen 191 1. Deutsche Tiefsee-Exped. Bd. 19, p. 220. Taf. 22, Fig. 9. Textfig. 13. 



Description. — The bell is somewhat higher than a hemisphere, the gelatinous substance 

 very thick, evenly rounded at the top, gradual!)' tapering towards the bell margin. The base of the 

 manubrium is broad, quadrangular, attached to the subumbrella along the arms of a perradial cross, 



