570 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
outside the peripheral circle; the spire is made up of 4 rods, which are united close to their apex and 
by a crosspiece near the middle. Calcareous ring (fig. 103) well developed, of moderate width, the 
radial pieces with not very long, stout posterior prolongations, deeply but narrowly separated. One 
stone canal, with a single, terminal madrepore plate. Polian vessel single. Color in life, pale to deep 
flesh-red, pink, or even purplish. 
Range. Pointe du Chene, New Brunswick, to Cuttyhunk; low water to 18 £ fathoms. 
Remarks. This and the following species are the rarest of the Woods Hole holothurians. It is 
admitted to this list on the strength of Verrill’s (’73b) statement that Professor Webster took it at 
Woods Hole, and on the existence of 3 small specimens in the collection of the U. S. National 
Museum, labeled “Off Cuttyhunk, 18} fathoms.” I have never seen Caudina alive, but it is said to 
be abundant at Revere Beach, Mass., at certain seasons. Strangely enough, however, trawling and 
dredging offshore in that region failed entirely to bring up specimens. Gerould’s (’96) admirable 
paper on this species leaves nothing to be said as to habits or anatomy. Nothing whatever is known 
of the development. Thiel’s variety, a.rrnata, was taken in 898 fathoms, in latitude 35° 44' 40" nn d in 
1,242 fathoms, in latitude 41° 24' 45". 
(Plate 11, (ig. 72; plate 13, figs. 105-108.) 
7. Trochostoma ooliticum (Pourtales). 
Chirodota ooliticum Pourtales, 1851. 
Molpadia borealis Sars, 1861. 
Molpadia oblitica Selenka, 1867. Verrill, 1873b. 
Trochostoma ooliticum Danielssen and ICoren, 1878. 
Trochostoma thomsonii Danielssen anti Korea, 1878. 
Trochostoma boreal e Danielssen and Keren, 1879. 
Description. Length 125 to 150 mm., with a diameter about one-sixth as great; the caudal por- 
tion of the body is only about one-eighth of the total length. Integument rather thin and usually 
quite smooth. Cloacal opening terminal, with minute surrounding papilla;. Tentacles 15 each 
usually with 2 (sometimes possibly more) digits. Deposits in the skin of 2 very distinct kinds ’irre«- 
ulai tables (figs. 106, 10/), and reddish or brown discoidal or ellipsoidal bodies (fig. 108) Tables 
sometimes wanting, apparently most frequent in young specimens and becoming less frequent 
with age; they are quite irregular in form; disk pierced by holes which vary greatly in number and 
size, and spire also variable in size and form. “Brown bodies” vary greatly in size and shade of 
color, for they may be mere grains or nearly as long as the diameter of a table disk and the shade 
ranges from brownish-yellow to a very deep reddish-brown; these “brown bodies” maybe rather 
scattered or more or less , crowded. As a rule, the fewer the tables the more the “brown bodies,” 
and vice versa. In typical ooliticum, there are no tables, and the integument is literally packed with 
brown bodies. ’ ’ Calcareous ring ( fig. 1 05) very stout, the radial pieces with very prominent posterior 
prolongations. Stone canal one, with a single madrepore plate. Polian vessel one. Color of alcoholic 
specimens very variable, according to the abundance of “brown bodies;” where they are very small 
nnd very few the color is dull gray, and the head and tail are always that color or lighter; where the 
“brown bodies” are more numerous they form brown patches on the surface; if still more abundant, 
the animal appears yellowish or reddish brown with gray spots of greater or less size; and finally, in 
typical ooliticum, the color appears uniformly deep brown or even almost black. Verrill (73b) says 
of a living specimen, “uniform flesh color.” ' 
Range. Banks of Newfoundland to south of Marthas Vineyard, and in the Arctic Ocean north of 
Norway and Siberia; reported from Florida Reef also; 18 to 600 fathoms, but usually over 50. 
Remarks. This distinctly northern form is admitted to the list of Woods Hole echinoderms 
solely on the record of one small specimen taken by Professor Packard and reported by Verrill (’73b). 
Even the locality of this specimen is in doubt, for on page 715 Verrill says, “Off Block Island, 29 
fathoms, sandy mud,” while on page 510 he says “ 15 miles east of No Mans Land,” and Block Island 
is 30 miles west of No Mans Land. The genus Trochostoma is probably more imperfectly known and 
its legitimate species less well defined than any other genus of holothurians. After the examination 
of a fairly large series from the collection of the U. S. National Museum, I am convinced that the 
differences which were supposed to separate ooliticum and boreale are unimportant and that Sara’s name 
is really a synonym of Pourtales’s. I can not agree with Ludwig (1900), however, that arcticum v. 
Marenzeller is identical with boreale, for specimens of the former are easily separable from the latter 
by severaI R°od characteristics. As to Verrill’s turgidum, if the characters given are constant it is 
also a good species. 
