108 
THE VOYAGE OF H.M.S. CHALLENGEE. 
Deposits — irregularly formed, perforated simple plates alone, 
seldom together with small rosettes or rods ; sometimes the plates 
are rod-like but with holes, 
a. Calcareous ring well developed, with posterior prolon- 
gations. 
Cucumaria africana, Semper, 1868. 
Body nearly cylindrical. Eadial pieces of the calcareous ring composed of a main part 
and two separate posterior prolongations. Deposits — large plates with short spines. 
Habitat — Querimba (Semper), Mauritius (Haacke, Ludwig). 
Calcareous ring well developed, hut devoid of posterior 
prolongations.^ 
Cucumaria hyndmanni (Holothuria), Thompson, 1840 ; Forbes, 1841 ; Diiben and 
Koren, 1845 ; v. Marenzeller, 1874. 
Body subcylindrical, slightly tapered posteriorly. Deposits— thick, nearly smooth 
perforated plates, all alike. Terminal plate of the pedicels incompletely 
developed or rudimentary ; supporting rods pierced with one hole (or more) at 
the middle, and one at each end. 
Habitat. — West coast of Scandinavia, south of the Arctic circle (Diiben and Koren, 
Danielssen, Sars, Mobius, Storm, Ludwig), British Islands (Forbes, Norman, 
MTntosh, Herdman, Thompson), Mediterranean Sea (Grube, v. Marenzeller, &c.). 
(Mus. Holm.) Numerous specimens dredged off the west coast of Sweden. The 
crowded, perforated plates are of an irregularly rounded form, smooth, thick, 
solid, and swollen in appearance ; among these are found some thinner and 
more finely constructed ones. Often the plates are slightly elongated or oval, 
with one end slightly narrower, bent obhquely outwards from the body of the 
a nim al, and rough from some minute spines or elevations. The numerous rods 
of the pedicels bear at the middle a short third arm, reminding one of a kind of 
spire. A single Pohan vesicle and madreporic canal. Calcareous ring devoid of 
posterior prolongations. 
“ Porcupine ” Expedition. — A few specimens dredged at Station 23, July 2, 1869, at 
a depth of 420 fathoms. 
Cucumaria exigua, Ludwig, 1875. 
Body cylindrical. Ventral pedicels more numerous than the dorsal. Deposits — large 
internal, and smaller external smooth perforated plates. Pedicels with rudi- 
mentary terminal plate, x -shaped bodies and large perforated supporting rods. 
Habitat. — China Sea and Chili (Ludwig). 
* In Cucumaria frauenfeldi and Cucumaria kirchsbergvi the calcareous ring is unknown. 
