Premature Form.—In early stages of growth the body is much more pentagonal
in form and usually lighter in colour, which not unfrequently approaches a pinkish or
flesh tint. The ambulacral sucker-feet are well spaced and arranged in single almost
straight lines. In a small specimen 9 millims. in length the two dorsal ambulacral
series are not so fully developed as the three ventral ; they contain fewer suckers; and
these are arranged in an almost straight line, except at the extremities, where the zigzag
alternating character of the series is clearly manifest, The oral tentacles, although
only partially extended in the specimen under notice, are already thick, frondose, and
many times divided, whilst the body-skin is filled with regularly-spaced calcareous
spicules roundish in form and punctured with holes, the solid interspaces being broader
than the apertures. Comparing this individual with another somewhat larger, 20
millims. in length, it will be noted that the body is proportionately more elongate, the
ambulacral feet more numerous, and now arranged distinctly in double rows of alter-*
nating suckers. The tentacular plume is slightly fuller, but still exactly the same in
general character as in the earlier stage; in fact the changes above noted are the only
conspicuous accompaniments of increased size perceptible to the naked eye. On micro-*
scopic examination, however, of the larger specimen it is found that no spicules are
present in the skin; and this is a feature which at once constitutes the most striking
difference between the two stages of growth. Such a circumstance is very remarkable ;
and although we are unable to say, with the limited amount of material at our disposal,
whether this is a state of things which always obtains, at least two other individuals, of
succeeding and still premature stages of growth, are equally wanting in spicules—a
character which, as previously observed, is not unfrequent in the adult form of
C. frondosa.
I t is noteworthy that the features presented by the young specimen of 9 millims.
accord exactly with those given by Liitken as characterizing C. minuta, Fabr, (excepting,
we imagine, the tentacles); but on this point Liitken does not say much, as these organs
were only partially extended in his specimen. If the view, therefore, which is here
taken be correct, it would lead naturally to the deduction that C.jninuta is nothing
more than the young of G. frondosa. Before this can be-definitely asserted, however,
the examination of the growth-phases in a greater number of examples of the present
species would be desirable; still we feel bound to say, after a very careful study of all
the available material, that we are unable to separate the young form above described
from the series of undoubted C. frondosa, the only feature in which it differs altogether
from the older stages being the presence of the calcareous bodies in the integument.
From the description given, it would seem that the Holothuroid namea by Forbes
and Goodsir C. fucicola is a young form of the present species, a determination now
generally concurred in by most naturalists,
Variations.—Amongst the list of synonyma will be found Bothryodactyla grandis,
Ayres, which we have been led to include rather from a diffidence against dissenting from
the opinion of so many eminent writers upon Holothuroids than from personal conviction.
Indeed there would seem to be great doubt about the absolute identity of this form ;
for, although the main characters recited in the cursory description accord well enough
with those of C. frondosa, they are by themselves quite insufficient for comparative
determination; whilst, on the other hand, it is definitely stated that the calcareous sup-
ports, though few, | are in the form of slender, perforated, crested spicula, similar to
those’found in Thyme and Thymidum’’ (l. o. p. 63). Such crested spicules certainly
do not occur in any specimens of G. frondosa from the North-European seas; whilst
from the fact that they are specially noted by Mr. Ayres (and it is a feature muc
more readily passed over than not) we are inclined to regard Bothryodactyla grandis, if
not an independent species, certainly with but little doubt as a well-marked variety.
In further support of this opinion it maybe noted that Sars examined specimens of the
American C.frondosa both &om Massachusetts and Fundy Bay, and specially asserts
their identity with the European type.
Distribution.
a. Greenland: Godhavn, lat. 69° 14' N. (Stimpson, iMfken,1 Valorous’ Beeped.). ^
b. Worth o f American Continent: Assistance Bay, about lat. 74° N. (Penny’s
Earned.), the most northern locality on record; Labrador (Verrill); St. Georges Bank,
30 fms. (Verrill); Grand Manan, low-water, stony bottom (Stimpson)-, Massachusetts
(Gould)-, Eastport, 20 fms., stony bottom (Verrill); Gulf of Georgia (SelenJca);
l Florida Eeef, 118 fms. (Powrtales)-, San Francisco (Ayres).
c. Worth o f European Continent: Spitzbergen (Liitken); Scandinavian coasts, Ice.
land, Faeroe Islands, Shetlands, British Islands.
Descriptim o f the Illustrations o f this Species'on Plate I.
Fig. 1. A medium-sized specimen: natural size.
2. A young specimen of the same species: natural size.
Cucumaria calcigera (Stimp.), SelenJca. Plate I, Figs. 3-8.
1851. Pentacta calcigera, Stimpson, Proceed. Boston Soo. Nat. Hist. vol. iv. p. 67.
1852. ? Cucumaria Hyndmanni, Forbes, Sutherland’s Jourual of a Voyage &c. vol. n. Append, p. ccxiv.
1857. Cucumaria Eorenii, Liitken, Vid. Meddel. N. Forening i Kjbbenhavn, 1857, p. 4.
1866. Pentacta calcigera, Verrill, Proc. Boston Soo. Nat. Hist. vol. x. p. 352.
1867. Cucumaria Korenii, Selenka, Zeitsch. f. wiss. Zool. Bd. xvii. p. 350.
1867. Cucumaria calcigera, Selenka, Zeitsch. f. wiss. Zool. Bd. xvii. p- 351.
1868. Cucumaria calcigera, Semper, Eeisen im Archipel der Philippines Holothurien, p. 53.
1868. Cucumaria Hyndmanni, Semper (pars), ibid. p. 269.
Body elongate and cylindrical, the posterior third tapering gradually to a fine
extremity; anterior end more rounded, and the median thickness of the body maintained
till very much nearer the oral region. The body is generally more or less curved
to one side, sometimes through more than half a circle, which gives to this species a
crescent- or even horseshoe-shaped contour. The ambulacral feet are arranged in single
pairs, and form five narrow, equally-developed bands. The suckers are placed very
closely together; consequently the number extending from tip to tip is proportionally
great, whilst sometimes, in the middle part of a hand, the pairs become reduplicated by