568 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
more or legs blunt and rounded according to amount of contraction. Cloaeal opening terminal, 
surrounded by 5 groups of slender papillae; just within the cloaca is a well-developed calcareous ring 
(figs. 101-102) with 5 prominent radial projections, which appear from the outside as teeth, and are 
usually referred to as “anal teeth.” Tentacles 10, the 2 ventral much smaller than the others, which 
are capable of considerable extension and are much branched. Pedicels rather small, very numerous 
all over the body, occasionally divided by very narrow lines into 5 broad, apparently radial, bands; 
many of the pedicels of the dorsal side taper to a point, and are thus more or less papilliform. 
Calcareous deposits in adults, wanting in most parts of the body wall, but present at each end of the 
body, and in the pedicels and tentacles; more numerous in young than in old individuals. These 
deposits are in the form of tables (fig. 97), plates, and rods; tables with a more or less square disk, 
perforated by about 8 holes, and a spire made up of 4 rather short rods, with one cross bar, ending 
in single teeth. Such tables are confined almost wholly to the two extremities of the body. In 
the pedicels, which are provided with a large terminal plate (fig. 98), the disks of the tables are 
elongated and curved to form supporting rods, and as such they often lack spires (fig. 99). In the 
tentacles the calcareous supporting rods (fig. 100) are so numerous as to make the trunk and principal 
branches almost rigid, and occur even to the tips of the smaller branches; around the base of the 
tentacles are some scattered plates perforated by six or more holes. In very young individuals, 
specimens an inch long or less, the body wall is often crowded with tables. Calcareous ring (fig. 95) 
well developed, rather stout, the radial pieces with moderately long, slender prolongations. Stone 
(anal single, with a large madrepore plate (fig. 96). Polian vessels usually 1 or 2. Color in life dull 
brown or black, the pedicels lighter, often quite reddish, the disks frequently yellow. 
Range . — Vineyard Sound to Texas, low water to 10 fathoms. 
Remarks . — This is undoubtedly the best known, to American students, of the Woods Hole 
holothurians, as it is the form commonly used for laboratory work. Hadley Harbor furnishes most 
of this material, Thy one being abundant there, but it is also to be found at Waquoit and near 
Cuttylmnk. Verrill (’73b) reports it from Buzzards Bay and Vineyard Sound. Usually it lies buried 
in soft mud in shallow water, either the posterior end alone or both ends above the surface. The 
currents of water repeatedly and continuously driven from the cloacal opening are often quite 
apparent, especially in very shoal water. The food consists of the fine organic particles gathered by 
the tentacles. Although this species apparently breeds in the summer, nothing is known of its 
development. In the winter of 1903 a number of very small specimens were washed up on the 
Buzzards Bay bathing beach at Woods Hole, after a period of heavy westerly winds, in company with 
specimens of Oucumaria pulcherrima. Mr. Gray kindly sent them to me for examination. 
4. Thyone scabra Verrill. (PI. 11, fig. 71; pi. 13, figs. 91-94.) 
Tliyone scabra Verrill, 1873a. 
Description . — Length up to 90 mm. (Theel), usually much less; Verrill says, “Length, in alcohol, 
about 2 inches.” All the specimens which I have seen from the Woods Hole region were less than 
50 mm., with a diameter of about 8 mm. Posterior third of the body quite attenuate to a rather sharp 
point. Cloacal opening terminal, with 5 sets of small papillae, but, so far as could be determined from 
preserved material, without the so-called “anal teeth.” Tentacles 10, branched from the base, the 2 
ventral smaller than the rest, which are not very large. Pedicels rather long and slender, somewhat 
rigid, quite numerous, and irregularly arranged, provided with terminal plates. Calcareous deposits 
very abundant, especially in pedicels, and tending to form a rather brittle, thin, and very rough layer 
over the whole body surface; deposits consist chiefly of tables (fig. 93) with more or less irregular disk, 
pierced by 6 or more holes ( Verfill says 20 to 24), and a more or less prominent and rather solid spire, 
made up of 2 or 3 stout vertical rods, connected by 1 or 2 crossbars and terminating in a number of 
teeth; in pedicels, disks of tables elongated, more or less bowed, with 4 holes, and ends expanded and 
perforated; in tentacles, numerous supporting rods (fig. 94), which are usually more or less perforated, 
especially at ends. Calcareous ring (fig. 91) well developed, radial pieces with a remarkably deep 
notch and long, slender prolongations posteriorly. Stone canal single with a large madrepore plate 
(fig. 92). Polian vessel usually single. Color in life not recorded; alcoholic specimens are brown or 
yellowish-brown, pedicels lighter. 
Range . — Georges Bank and Bay of Fundv to Vineyard Sound, Narragansett Bay, and perhaps 
even to Delaware (Theel); 10 to 640 fathoms. 
