MUSEUM OF COMPARATIVE ZOOLOGY, 51 
involuted and the tentacles concealed. In this condition the upper extremity 
is covered with convergent, strongly raised folds or crest-like’ ridges, larger and 
smaller ones irregularly alternating. These crests correspond in number to the 
tentacles, and run up somewhat on their outer bases; the larger ones, which 
correspond to the inner or primary tentacles, can be traced inward between the 
outer tentacles, until they run to and coalesce with the external basal portion 
of the inner ones. The upper portion of the column, covered by these ridges 
and crests, is strongly differentiated from the part below it, for its integument 
is soft and lubricous, and usually decidedly red or pink in color during life; 
this portion, in fact, like the tentacles, secretes an abundant mucus, which is 
strongly phosphorescent. A row of large rounded warts or tubercles, or a 
more or less marked, transverse, verrucose ridge separates this upper or sub- 
marginal zone from the general surface of the column, which is firmer, more 
or less verrucose, and generally wholly or partly covered with a dirty brown- 
ish, somewhat chitinous, tough and firmly adherent coating, which is strongly 
wrinkled in contracted specimens, and sometimes has hydroids, bryozoa, and 
even such shells as Anomia adhering to its surface. This covering is often 
partially, and sometimes wholly wanting, especially in very large examples. 
It often persists on the larger upper verruce, even when absent elsewhere, and 
in some rather exceptional specimens it is much thickened on these warts, or 
even forms for them hard conical tips, sometimes affecting thus only the upper- 
most row, but at other times several series of them. 
The most common form (Fig. 6) in expansion has the body more or less 
cylindrical, varying to hour-glass shape. The base may be broad and flat, 
often much broader than the body, and adherent to stones and shells; it may 
closely clasp cylindrical worm-tubes, branches of gorgoniz, etc.;* or it may 
be deeply concave and bulbous, and enclose a mass of sand and mud.t Speci- 
mens with these different styles of base may all occur in the same locality, 
without other corresponding differences. 
The column is covered with hard, prominent, and persistent verruce, ar- 
ranged in pretty regular vertical and transverse rows, the upper ones becoming 
larger and more prominent, often with a hard, sharp tip, the lower ones grad- 
ually diminishing. At a short distance below the upper edge there is a trans- 
verse ridge, or row of large tubercles, above which the character of the tubercles 
and of the integument abruptly changes, the rounded verruce being replaced 
by longitudinal ridges and crests, alternately larger and smaller. In other 
cases the verruce become nearly obsolete below the middle, or are indicated 
only by longitudinal and transverse wrinkles. In very large examples the 
* This habit is still more common with several other species from the same 
localities. Among these are Actinauge nexilis V., Sagartia abyssicola, S. Acanelle 
V., ete. ‘ 
t These enclosed masses of bottom often afford us accurate data as to the pre- 
cise nature of the bottom sediments, with the relative proportions of mud, sand, &c. 
in their original condition, for this matter is clasped so tightly that no part can 
wash out. 
