. The Danish Ingolf-expedition. Marine animals -- Arctic regions; Scientific expeditions; Arctic regions. HYDROIDA 55 From the reptant stolons proceed polyp stems up to 12 nmi. long, generally nnbranched; more rarely 2—4 polyp stems proceed from a common trunk, 1—2 mm. high. The polyps attain a lengtli of mm., and are fusiform, with 6—12 tentacles placed in a whorl. Below the tentacles the polyp is surrounded by a pseudohydrotheca, which it is very difficult to observe on the pohp when wliollv extended. In general it is jellied and developed. The polyp stems are, particularly i
. The Danish Ingolf-expedition. Marine animals -- Arctic regions; Scientific expeditions; Arctic regions. HYDROIDA 55 From the reptant stolons proceed polyp stems up to 12 nmi. long, generally nnbranched; more rarely 2—4 polyp stems proceed from a common trunk, 1—2 mm. high. The polyps attain a lengtli of mm., and are fusiform, with 6—12 tentacles placed in a whorl. Below the tentacles the polyp is surrounded by a pseudohydrotheca, which it is very difficult to observe on the pohp when wliollv extended. In general it is jellied and developed. The polyp stems are, particularly in their part, irregularly wrinkled. The very large gonophores show no medusoid structure; they are attached to the reptant sto- lons by a short stem. Material: Greenland (Lille Hellefiskebanke) (the original specimen of Garvcia groenlandica Levinsen). An examination of the original specimen of Garvcia groenlandica shows no difference at all from Norwegian specimens of Pfrigo)iiinus roseits. The species are no doubt identical. If we compare Kramp's drawing of Garvcia groenlandica (1911, pi. XXV, fig. 6) with Jiiderhohn's figure of Pc- rigoniniHS roscus (1909, Taf. Ill, Fig. 7), there ma}-, at the first glance, seem to be some jjoints of difference. Thus the stems of the siDccimen mentioned by Kramp are much shorter. But this character proves of little significance if we compare the specimen with a larger colony, where, as a matter of fact, the length of the polyj) stems varies greatly. A greater stress might, on the other hand, be laid on the apparently great difference between the pseudohydrothecae as represented in the two figures. However, much depends on the contraction of the polyps and on the state of preservation, as is plainly to be seen bv an inquir\' into a larger material. I have several times had the opportunit\- of observ-. zoom. 600m. looom. zooom. Text-fig. R. The occurence of Perigonimiis roseia in the Nortliern Atlantic. (In the hatched region th
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Keywords: ., bookcentury1800, bookdecade1890, booksu, booksubjectarcticregions
