MUSEUM OF COMPARATIVE ZOOLOGY. 11 
end of the calcareous joints, but sometimes from the middle. The calcareous 
joints are ivory-white, elongated, round, slightly enlarged at the ends, usually 
faintly and often indistinctly striated longitudinally, appearing smooth to the 
naked eye, but finely granulous under a lens; they are tubular, having a cen- 
tral tube equal to about a third or a fourth of their total diameter. Chitinous 
joints are usually golden yellow or bronze-color, sometimes plain brown, short, 
scarcely longer than thick in the larger branches, about twice as long as thick 
in the smaller ones, where they become translucent and brownish or amber- 
color, without the metallic lustre seen in those of the larger branches. 
The calicles are usually, in dried specimens, prominent, elongated, some- 
what expanding toward the end, and are crowded nearly. equally: over the 
whole surface; they are covered with large, conspicuous, acute spicula, which 
form, at summit, eight sharp projecting spinous points. The ceenenchyma is 
thin, translucent, yellowish, filled with long and large fusiform, conspicuous 
spicula. ’ 
A large specimen, well preserved in alcohol, from the Gloucester fisheries, 
lot 367, shows remarkable variations in the length and form of the calicles. 
Over most of the branches they are very long and prominent, constricted in 
the middle, with an expanded base and enlarged summit, crowned by eight 
prominent spines, surrounding the incurved and nearly retracted tentacles 
(Fig. 3a). In this form of calicle the length is two to three times the average 
diameter. But on other branches the calicles are only prominent, subconical 
verruce, broadest at base, with the summit narrow, and the spines but little 
prominent (Fig. 3b); these are often about as broad as high. Intermediate 
forms also occur on this specimen. The calicles are irregularly but rather 
uniformly scattered over the whole surface, and are mostly separated by spaces 
two or three times as great as their breadth, though some are in contact at 
their bases. The surface of the ccenenchyma and calicles in this example is 
covered with a soft integument, which nearly conceals the spicules, except at the 
border of the calicles; but they become conspicuous when dried. This exam- 
ple also has the basal part, which is deeply divided into irregular, palmate, 
flattened lobes, or root-like expansions, by means of which it anchors itself in 
the mud. 
The large projecting spicula of the calicles are fusiform, usually more or 
less bent, and either acute at both ends or acute at the outer end and obtuse 
at the inner (Fig. 3c, ¢); the surface is nearly smooth, or only slightly rough- 
ened in longitudinal lines on the basal part, or sometimes throughout, but in 
many cases the longitudinal lines of points become more evident on the inner 
end. They have a large yellowish brown nuclear portion. The larger of 
these measure 4.40 by .35, 4.10 by .33, 4.10 by .30, 3.90 by .25, 3.80 by .30, 
3.70 by .22, 3.60 by .30, 3.00 by .30, 3.00 by .20 mm. 
With these, below the margin, and in the polyps, there are many smaller 
and more slender, partly fusiform, partly oblong or rod-like spicula, with both 
ends similar, and either acute or obtuse, and usually distinctly but finely 
lined and roughened longitudinally and obliquely, especially near the ends, 
