. The Danish Ingolf-expedition. Marine animals -- Arctic regions; Scientific expeditions; Arctic regions. 38 HOLOTHURIOIDEA Ventral retractor fastened closely to the margin of the sole. One polian vesicle and a single stone-canal. Respiratory organs relatively well developed. Calcareous ring without any special characteristics, showing that the ten tentacles are all of equal Textfig. 41. Psolus: hypsinoius. Dorsal side of type specimen. Calcareous deposits of the sole small four- to seven-holed plates supplied with a few knobs. Most closely related species: Psolus dubiosus Ludwig and He
. The Danish Ingolf-expedition. Marine animals -- Arctic regions; Scientific expeditions; Arctic regions. 38 HOLOTHURIOIDEA Ventral retractor fastened closely to the margin of the sole. One polian vesicle and a single stone-canal. Respiratory organs relatively well developed. Calcareous ring without any special characteristics, showing that the ten tentacles are all of equal Textfig. 41. Psolus: hypsinoius. Dorsal side of type specimen. Calcareous deposits of the sole small four- to seven-holed plates supplied with a few knobs. Most closely related species: Psolus dubiosus Ludwig and Heding. Type specimen: "Ingolf" St. 27. Description: The specimens are all rather small, the largest, from St. 32, measuring not more than 14 mm in length and 6 mm in width as well as in height. They are pure white, and the scales along the sides are smooth, whereas those along the dorsal inter- ambulacrum are usually supplied with one to three small but distinct knobs. There are two distinctly different sizes of scales, as the few very large ones are intermingled with rows of small ones. All the scales are imbricating, a feature which is most remarkable for the small scales. All the marginal scales are small and form a thin and sharp edge. The skin of the sole is fairly thin but not translucent, partly on account of the numerous deposits. The tube-feet are only found along the margin of the sole, where they are placed in two rows, an inner one with large tube-feet and an outer one with much smaller ones. The inner tube-feet are usually of a some- what varying size and are often alternately large and small. They are placed in a fairly regular row, only at the two ends of the unpaired ambulacrum there is a group of tube-feet. The calcareous deposits of the sole (textfig. 43 1-2) are small flat plates with normally four large and a few smaller perforations, and all the fully developed plates are supplied with some fairly large distinct knobs. Remarks: This species resembl
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Keywords: ., bookcentury1800, bookdecade1890, booksu, booksubjectarcticregions
