48 
THE VOYAGE OF H.M.S. CHALLENGER. 
SUKVEY OF THE GENERA AND SPECIES, HITHERTO KNOWN, REFERRED 
TO THE APODOUS PNEUMONOPHORA. 
Family II. M o L p a d i d a:. 
Tentacles simple, unbranched or digitate. Body tapering posteriorly into a narrow, 
longer or shorter caudal portion. Deposits of various shapes ; anchors of a 
strange appearance very seldom occur, never wheels. 
Genus 1. Ankyroderma, Danielssen and Koren, 1879 and 1882. 
Retractor muscles absent. Calcareous ring with five bipartite posterior prolongations. 
Tentacles fifteen, three-lobed. Deposits — excepting other calcareous bodies, 
anchors in connection with groups of spoon-like rods, or very seldom irregularly 
formed anchor-plates. 
Ankyroderma Jeffrey sii, Danielssen and Koren, 1879 and 1882. 
Deposits of three kinds — groups of five to six spoon-like rods arranged so as to form 
a star, with the enlarged perforated ends forming the centre of the star and 
supporting an anchor with a very long shank or handle and slightly serrated 
flukes ; tables with the irregular perforated disk more elongate at the 
extremities of the body, and with a spire, three-armed at the base, terminating 
in a few spines ; finally numerous small round or elliptical wine-red bodies of a 
concentric structure. 
Habitat . — Northern coast of Norway and the Arctic Sea, north of Norway : depth 
varying from 127 to 459 fathoms (Danielssen and Koren), Barents Sea (Hoffman). 
Ankyroderma affine, Danielssen and Koren, 1879 and 1882. 
Deposits of four kinds — stars with anchors, like those in the preceding species, but 
more numerous and arranged in nearly regular rows ; tables like those in the 
preceding species, but much more irregular ; spicules consisting of several (five 
to eight) slender arms radiating from a common centre, which carries an out- 
wardly directed process or spire ; finally, very rare, minute wine-red bodies. 
Habitat . — Arctic Sea, between Norway and Beeren Island, at a depth of 191 fathoms 
(Danielssen and Koren). 
The fifth kind of deposits, viz., the conglomerates of calcareous grains and prisms, may 
probably be the result of artificial processes. 
