. The Danish Ingolf-Expedition. Scientific expeditions; Arctic Ocean. 56 PORIFERA. 208 fathoms (The Fishery investigation steamer "Thor"). The localities are in the Den- mark Strait. 12. H. dubia n. sp. PI. VI, Fig. 8. Incrusting; surface finely hispid. Spicula: megasclera ; the skeletal spicules acanthostyli with a small head, divided into two groups, large, only spined below, 0-34—-o-jS""", small, entirely spined, 0-/0 — 0-23"""; the dermal spicules strongyla 0-26—0-32"""; microsclera chela' arcuata 0-040—0-05/""". O
. The Danish Ingolf-Expedition. Scientific expeditions; Arctic Ocean. 56 PORIFERA. 208 fathoms (The Fishery investigation steamer "Thor"). The localities are in the Den- mark Strait. 12. H. dubia n. sp. PI. VI, Fig. 8. Incrusting; surface finely hispid. Spicula: megasclera ; the skeletal spicules acanthostyli with a small head, divided into two groups, large, only spined below, 0-34—-o-jS""", small, entirely spined, 0-/0 — 0-23"""; the dermal spicules strongyla 0-26—0-32"""; microsclera chela' arcuata 0-040—0-05/""". Of this species we have a specimen growing on a stone together with specimens of H. Kochleri, baculifera Tops., curvichela, Ezirypon sp. and Plocamia sp. The specimen has a greatest extent of only iomra, and it is very thin. The colour (in spirit) is whitish. The surface is finely hispid. The dermai membrane is thin, somewhat richly charged with chelse. Oscula and pores were not observed. The skeleton. The dermal skeleton consists of bundles of dermal spicules, stretching obliquely from the skeleton below up to the surface; the bundles may vary with regard to the number of spi- cules contained, but it is generally not great. The main skeleton is constructed in the typical way and consists of erect acanthostyli with their heads based on the substratum, the longest of them reach to the dermal membrane, and it would seem that they penetrate through it. Spongin seems to be present at the base, but to a very slight degree. Spicula: a. Megasclera. 1. The skeletal spicules are acanthostyli; they are divided into two rather well separated groups; the larger styli are straight, or most frequently slightly curved, they have a small head-swelling and they taper evenly out into a long apex; on the head-swelling there are somewhat large spines, but for the rest the styli are nearly smooth, only on the lower part, near the swelling, they are slightly gritty; the small styli are simila
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectscienti, bookyear1910
