EEPORT ON THE HOLOTHUEIOIDEA. 
149 
Genus 12. Oreula, Troschel, 1846. 
Tentacles fifteen, five smaUer alternating with ten larger. Ambulacral appendages 
in the sliape of pedicels distributed over the ambulacra as well as interambulacra; 
an arrangement of them in rows seldom discernible on the ambulacra. 
1. Deposits in the hody-wall itself absent. 
Oreula harthii, Troscbel, 1846; Lutken, 1857; Duncan and Sladen, 1881. 
Pedicels irregularly scattered. Calcareous ring of ten simple pieces, all bifurcate 
posteriorly, the radial terminating anteriorly in two points, the narrow interradial 
in one. 
Habitat . — Greenland (Lutken, Norman, Duncan and Sladen), Labrador (Troschel) 
Sea of Kara (Stuxberg), (?) Spitzbergen (Ljungrqan). 
Oreula limaeonotus {Cladolabes), Brandt, 1835; Ludwig, 1881. 
Habitat . — Boninsima (Brandt). 
From the researches hitherto made, it is impossible to state whether this species is 
distinct from the preceding or not. The statement that Oreula limaeonotus has 
several, up to nine, Polian vesicles, while Oreula harthii has only a single one, 
seems to be of Kttle or no importance. 
2. Deposits in the hody-ioall itself present. 
Oreula tenera, Ludwig, 1875. 
Pedicels irregularly scattered. Calcareous ring of ten simple pieces, “ aU ” with two 
posterior slender prolongations composed of several separate pieces or joints. 
Deposits — very few tables and minute grains, the former composed of a 
roundish perforated disk and a spire built up of four (?) rods and one transverse 
beam. 
Habitat . — Upolu in Navigator Islands (Ludwig). 
Oreula hypsipyrga, von Marenzeller, 1881. 
Pedicels irregularly scattered. Calcareous ring of ten simple pieces, the radial alone 
with two long slender posterior prolongations composed of several separate 
pieces or joints. The ends of these prolongations are united with those of the 
adjacent radial pieces. Deposits — tables consisting of a roundish disk with 
numerous holes, and a central spire built up of four to six rods and several 
transverse beams ; the spire terminates in several spines. 
Habitat . — Japan or China (von Marenzeller). 
