10 



P. L. KRAMP. 



[REP. OF THE "MICHAEL" SARS NORTH 



genus which shows most points of connection with the 

 Tiaridae. 



9. Laodfcea undulata (Forbes and Goodsir). 



Stat. 99. Lat. 57° 45' N, Long. 13° 40' W (near 

 Rockall), August 6th 1910. Young-fish trawl with 50 in. 

 wire. 



Small pieces of 5 — 7 individuals. The edge of the 

 mouth is complexly folded. The gonads end in a distance 

 of 2 — 3 mm. from the ring-canal. The tentacles are very 

 numerous and situated closely together. Between every 

 successive pair of tentacles there is a small projection, in 

 some cases stiil bearing a cordylus. If cirri have been 

 present they have all been broken off. A small but 

 distinct ocellus is found at the base of every 3—5 of the 

 tentacles. 



As to synonomy and varieties, see Browne 1907, 

 Ann. Mag. Nat. Hist. ser. 7, vol. XX, p. 459, and Mayer 

 1910, Medusae of the World, I, pp. 201—204. 



10. Obe/i'a sargassi (Broch). 



The hydroid: 

 Obelia hyalina Clarke 1879, Bull. Mus. Com p. Zool., Harvard 



Coll., vol. 5, Nr. 10, p. 241, PI. 4, fig. 21. 



Congdon 1907, Proceed. Amer. Acad. Arts and 



Sci., vol. 42, p. 468, figs. 7—9. 

 Laomedea sargassi Broch 1913, Rep. Sci. Res. "Michael Sars", vol. 



Ill, Part. I, p. 13. 



Sargasso Sea, June 26th 1910. Sargassum at the 

 surface, several specimens. 



Stat. 69, Lat. 41° 39' N, Long 51° 04' W (Sargasso 

 Sea), June 26th 1910. Sargassum at the surface, several 

 specimens. 



Among the material brought home by the "Michael 

 Sars" there are a couple of glasses containing a number 

 of minute medusae of the genus Obelia. According to 

 the labels the specimens have been taken on Sargassum, 

 which probably means, that they arise from the gonothecae 

 of some hydroids growing on the Sargassum, undoubtedly 

 Laomedea sargassi Broch (Syn. Obelia hyalina Clarke), 

 which is very common on floating sea-v/eed and has been 

 found in great abundance by the "Michael Sars" (see 

 Broch op. cit). The liberated medusa has not been 

 described. It is described here with the name: 



Obelia sargassi. The medusae have the general 

 appearance of the genus Obelia. All the specimens seem 

 to have been preserved immediately after their escape 

 from the gonothecae. The diameter is about 0.2 mm. 

 They have 32 — 33 tentacles, a comparatively large number; 

 most other species of Obelia have 24, seldom 28 tentacles 

 at the time of liberation. — Gonads are not visible. 



//. Tiaropsis mu/ticirrata (M. Sars). 



Tliaumantias multicirrata M. Sars 1835, Beskriv. og Iagttag., p. 26, 



PI. 5, fig. 12 a— c. 

 Tiaropsis diademata L. Agassiz 1849, Contrib. Nat. Hist. Acalephs 



of N. America, p. 289, PI. 6, figs. 1—18, 



PI. 8, fig. 11. 

 St. Johns, Newfoundland, July 5th 1910, surface. 

 37 individuals, most of which are 10—12 mm. in 

 diameter, only some few specimens being of smaller size. 

 The smallest specimen is 6 mm.— There is no specific 

 difference between the American T. diademata Agassiz 

 and the European T. multicirrata M. Sars. 



12. Halopsis ocellata A. Agassiz. 



Halopsis ocellata A. Agassiz 1863, Proceed. Boston Soc. Nat. Hist., 



IX., p. 219. 



1865, North. American Acalephs, p. 99, 



figs. 143—150. 

 Haeckcl 1879, System d. Medusen, p. 217. 

 Fewkes 1888, Bull. Mus. Comp. Zool., vol. XIII. 

 Nr. 7, p. 233, PI. Ill, fig. 3. 



Hargitt 1904, Bull. U. S. Bureau of Fisheries, vol. 

 24, p. 51. 



Mayer 1910, Medusae of the World, II, p. 323, 

 Bigelow 1914, Bull. Mus. Comp. Zool., vol.58, Nr. 

 2, p. 102. 



Stat. 94. Lat. 50° 13' N, Long. 11° 23' W (south- 

 west of Ireland), July 26th 1910, depth 1565 m. Ring- 

 trawl with 1500 m. wire. — 1 specimen. 



Stat. 97. Lat. 56° 15' N, Long. 8° 28' W (between 

 the Hebrides and the north coast of Ireland), August 4th 

 1910, depth 139 m. Ringtrawl with 50 m. wire. — 2 spe- 

 cimens. 



Stat. 98. Lat. 56° 33' N, Long, 9° 30' W (south- 

 west of the Hebrides), August 5th 1910, depth 1000— 

 1360 m. Ringtrawl with 200 m. wire. — 1 specimen. 



Stat. 101. Lat. 57° 41' N, Long. 11° 48' W (between 

 the Hebrides and Rockall), August 6th— 7th 1910, depth 

 1853 m. 



a. Young-fish trawl with 1000 m. wire. — 1 specimen. 



b. Ringtrawl with 200 m. wire. — 1 specimen. 



Description: The umbrella is watchglass-shaped, 

 the gelatinous substance comparatively thick, particularly 

 so in the central part of the disk, evenly diminishing 

 in thickness towards the margin. The diameter of the 

 largest specimen is about 40 mm. The manubrium con- 

 sists of a flattened stomach and a short mouth-tube. The 

 stomach is circular or star-shaped; its diameter is 1 k— 1 U 

 of the diameter of the disk. The length of the mouth- 

 tube is about 4 mm.; the diameter at the narrowest part 

 (at a short distance below the stomach) is about V2 of 

 the diameter of the stomach. The lower (distal) part of 

 the mouth-tube is somewhat dilated, divided into four 



