. The Danish Ingolf-expedition. Marine animals -- Arctic regions; Scientific expeditions; Arctic regions. 78 HYDROIDA II opening, and a median proximal sarcotheca, the opening margin of which hardly reaches up to the middle of the hydrotheca; the sarcothecse have a dentate margin, and project far forward; they are adcanlinally split. The Iiydrotheca is laterally compressed; seen from the side, it is egg-shaped and pointed at the lower end. The hydrotheca has abcaulinally a median keel, running out into a large, hollow, generally sharply horn-shaped tooth, the free projecting part of which may
. The Danish Ingolf-expedition. Marine animals -- Arctic regions; Scientific expeditions; Arctic regions. 78 HYDROIDA II opening, and a median proximal sarcotheca, the opening margin of which hardly reaches up to the middle of the hydrotheca; the sarcothecse have a dentate margin, and project far forward; they are adcanlinally split. The Iiydrotheca is laterally compressed; seen from the side, it is egg-shaped and pointed at the lower end. The hydrotheca has abcaulinally a median keel, running out into a large, hollow, generally sharply horn-shaped tooth, the free projecting part of which may reach a length of up to ^'. that of the h^'drotheca; the cavity forms a continuation of the lumen of the hydrotheca. The hydrotheca margin has at the base of the mentioned projection a median abcauline tooth, and on either side four teeth, which become broader and less pro- nounced nearer the hydrocladium. The internodium has four to six inner ribs at the hydrotheca wall; an inner rib also bounds the lumen of the proximal sarcotheca on its lower end. The hydrotheca lacks inner ribs or septa. The gonothecfe are set on the stem, or more often on short, once dichotomicall)- divided branchlets proceeding from the basal internodium of the hydrocladium beside its proximal sarcotheca; the. Fig. XXXIX. Aglaophenopsis cornuta. "Ingolf St. 25. â a. Caiiline interno- dium of the primary tube, showing both sarcothecae of the upper pair. â b. Front view of the internode, showintr the abortive hydrotheca at the base of the apophyse above the proximal small branches bear as a rule a hydrotheca on each branchlet; more sarcotheca. (X 40I. , , , , i ,, .1 .1 tm rarel\- the one may ha\-e two hydrothecte, the other one. 1 he gono- theca is broad oval to pear-shaped; seen from the side it is somewhat more slender, with subterminal opening on the adcladial side and with a short upjjer lip, formed b>' the abcladial wall, which is domed forward roofwise over the opening. Material: "Ingo
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Keywords: ., bookcentury1800, bookdecade1890, booksu, booksubjectarcticregions
