. The Danish Ingolf-Expedition. Scientific expeditions; Arctic Ocean. 62 HYUROIDA II That Nutting (1900 p. 66) should refer this species to Plumularia must be due to his having had small or poorly developed colonies to deal with. From the "Ingolf" St. 55 we have a couple of splendid colonies showing the typical secondary hydrocladia of Polyplumaria in practically every branch, and richly furnished with gonangia. These are situated on the basal part of the hydrocladia — both primary and secondary, and partly also on the tubes of the stem. It might be imagined that the present specimen
. The Danish Ingolf-Expedition. Scientific expeditions; Arctic Ocean. 62 HYUROIDA II That Nutting (1900 p. 66) should refer this species to Plumularia must be due to his having had small or poorly developed colonies to deal with. From the "Ingolf" St. 55 we have a couple of splendid colonies showing the typical secondary hydrocladia of Polyplumaria in practically every branch, and richly furnished with gonangia. These are situated on the basal part of the hydrocladia — both primary and secondary, and partly also on the tubes of the stem. It might be imagined that the present specimens, with their typical Polyplumaria colonies, were specifically different from Nutting's Plumularia profunda. We found, however, besides the two mentioned, extremely luxuriant colonies, also a smaller, single pinnate colony, where only the basal hydrocladia were furnished with secondary hydrocladia, all the remaining hydrocladia being simple. Nevertheless, this colony is likewise fertile, and a fur- ther investigation of the larger colonies shows that here also the secondary hydrocladia are lacking on several branches. In all these colonies, the stem is polysiphonic. But from the "In- golf" St. 24 we have a quite young, sterile colony, where the whole stem is mouosiphonic; only at the bottom of the basal part is a secondary tube developed. Here then, we have the complete transition from Nutting's description to the typical yy Polyplumaria which the species represents in its fully developed form. The resemblance in detail will furthermore be seen from a comparison of the illustrations here given (fig. XXIX). The finding of Polyplumaria profunda in the northern Atlantic is highly interesting. The species is a typical deep sea „ , , lg" " . ' ,„, _,. form, previously known only from West Indian waters. We now Polyplumaria profunda "lngolf St. 24. ' r J J a. Hydrocladial internodium. b. internodium find, that it penetrates in deep water right up into D
Size: 991px × 2522px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectscientificexpedition
