. The Danish Ingolf-Expedition. Scientific expeditions; Arctic Ocean. 36 MEDUSAE. I. Ptychogena antarctica Browne (1907, more thoroughly described in 1910, p. 29) is distinguished from Ptycfiogena lactea by the fact that the gonadial lateral folds are shorter and not attached to the subumbrella, and by the colour, the base of the tentacles being, according to Browne, provided with red entodermal pigment; according to Vanhoffen (1912), who has refound the species in the material from the German South-Polar expedition, the organs are dark coffee-brown. There is one cordylus be- tween every succe
. The Danish Ingolf-Expedition. Scientific expeditions; Arctic Ocean. 36 MEDUSAE. I. Ptychogena antarctica Browne (1907, more thoroughly described in 1910, p. 29) is distinguished from Ptycfiogena lactea by the fact that the gonadial lateral folds are shorter and not attached to the subumbrella, and by the colour, the base of the tentacles being, according to Browne, provided with red entodermal pigment; according to Vanhoffen (1912), who has refound the species in the material from the German South-Polar expedition, the organs are dark coffee-brown. There is one cordylus be- tween every successive pair of tentacles, and in some of these cordyli Browne found nematocysts (see p. 4).. Chart III. Occurrence of Ptychogena lactea A. Agassiz in the northern Atlantic and adjacent arctic waters. The hatching denotes the southern limit of the occurrence in the Barents Sea, according to Linko. Vanhoffen (1912, p. 366) describes another species, Ptychogena aurea^ from four small speci- mens with about 32 tentacles and gold-yellow gonads with mature sexual products. Cordyli are not present. I am not convinced that this medusa belongs to the genus Ptychogena, but I will not deny the possibility. I have had at my disposal for examination 12 specimens of Ptychogena lactea from 9 different localities. In the following list I have also included some non-preserved specimens from Godthaab Fjord, Greenland, found by the "Tjalfe" expedition; in the journal of the expedition they are shortly but clearly described, so much so that they may be identified with complete Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Ingolf (Cruiser); Danish Ingolf-Expedition (1895-1896). Copenhagen : H. Hagerup
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectscienti, bookyear1919
