STAUROMEDUS.E TESSERA, TKSSERANTHA, TESSKH.MM \, m T\sTIJUM. 



523 



are only 4 simple, interradial, gastric cirri, one in each interradius of the central stomach above 

 (centripetal to) the 4 horse-shoe-shaped gonads. A single specimen was found hy the Chal- 

 lenger southeast of Kerguelen Island, Antarctic Ocean, on February 19, 1874. 



Tessera typus Haeckel, 1880 (//<;,/., p. 638), bell 8 mm. wide, 12 mm. high, pyramidal, 

 4-sided, elongate. 8 tentacles, 4 perradial and 4 interradial. of t-c|ual lengths, each nearly twice 

 as long as the bell-diameter. 6 to 8 gastric filaments in each interradius. 4 hoise-shoe-shaped 

 gonads in proximal half of subumbrella. A single specimen from the Indian Ocean, south of 

 Madagascar. 



Tesseranilm emuiettfns Haeckel, 1880 (Syst. der Medusen. p. 373; iSSi. Deep-sea Medusae 

 CJuillrtiyer Expedition, Zool., vol. 4, p. 50, plate 15, tigs. I to 8 1 differs from "Tessera 

 pritiifps" in being larger and in Inning id tentacles and numerous gastric cirri. The 

 medusa is 9 mm. high and 6 mm. wide. The tentacles are perradial, interradial, and adra- 

 dial, the largest being the first named, and the last quite short and apparently immature. 

 There is an ectodeimal pigment spot on the exumbrella side of the base of the 8 perradial 

 and interradial tentacles. A ridge of nettle cells extends toward the apex of the bell from 

 the base of each tentacle. These pigment spots and ridges are not seen in Tessera prince ps. 

 The numerous gastric cirri are arranged on both sides of the 4 interradial partial septa or 

 taeniola of the central stomach. The 4 interradial pits of the subumbrella are deeper 

 than in Tessera. Altogether all of the differences between Tessera and Tesserantha are such 

 as one would expect to find in one and the same medusa in advancing stages of growth. 



Tesserantha ennneetens was found by the 

 Challenger near the island of Juan Fernandez, 

 South Pacific, at a depth of 2,160 fathoms. It is 

 elaborately described by Haeckel, 1881. 



Tesserana scyphomeda Haeckel, 1880 (IbtJ., p. 

 638), has a goblet-shaped bell, 10 mm. wide, 15 

 mm. high. 32 tentacles equal each to each and not 

 quite as long as the bell-diameter. 4 simple rows 

 of gastric cirri. 4 horse-shoe-shaped gonads. 



Found in Bass Straits between Australia and 

 Tasmania. One specimen in GodefTroy Museum. 



Genus DEPASTRUM Gosse, 1858. 

 Depaitrum, GOSSE, 1858, Annals and Ma.?. Xat. Hist., vol. 1, ser. 3, 



r-4'9- 



Dcpastrum + Dtpastrtlla, HAF.CKEL, 1880, Syst. dcr Medusen, pp. 



376, 378. 

 Depastrum, DIXON, G. Y. and A. !'.. iS.|-,, Pror. Kov. Dublin Soc., 



\ 1. !\, p. iSo. B> \r MM\ i. i $94, Trans. Liverpool Bfol. Soc., 



vol. 7, p. 154. MAASj nio(>, K.iuna Arctica, Bd. 4, p. 500. 

 CarJuellii, ALIVHN, 1860, Rrport British Association, p. 143. Clark, 



1863, Boston Journal Nat. Hist., vol. 7, p. 546. 



The type species is Depastrum cyathiforfne of 

 the northern coasts of Europe, first described by M. 

 Sars, 1846, as Lucernana cyathiforme. Gosse, 

 1858, established for it the genus Depastrum. 



GENERIC CHARACTERS. 



Stauromedusnc with 16 clusters of tentacles, 4 

 perradial, 4 interradial, and 8 adradial, arranged 

 in one or in several rows around the bell-margin. 

 Tentacles are all similar each to each, and are hol- 

 low, and terminate each in a nematocyst-knob. 

 There may be one or more tentacles in each per- 

 radius and interradius. No marginal anchors. 

 With divided stomach-pouches as in the Cleistocarpidae. An unbroken marginal, subumbrella 

 ring-muscle. 4 small, interradial partial septa in the central stomach, leaving a wide, 

 marginal ring-sinus. 4 interradial horse-shoe-shaped gonads with their convexities inward 



FIG. 333. Tesserantha connectcns, after Haeckrl in Deep 

 sea Medusa. 1 of Chnllengrr Expedition. 



