366 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 97 
(absent from introvert); longitudinal muscle layer of postintrovert 
region divided into 21 to 23 muscle bands, rarely anastomosing; 
four retractors, the dorsals arising well in front of ventrals, which 
are separated from the nerve cord by two or three muscle bands; 
postretractor region about half body length; strong spindle muscle 
arising in front of the anus and attached at the posterior end of the 
body; intestinal spiral very long (60 to 62 coils); contractile vessel 
densely papillated posteriorly; nephridia free, opening a short dis- 
tance in front of anus; small coelomic papillae forming a transverse 
zone in front of nephridia; tentacular crown capitate; tentacles 
arranged in 12 double meridional series, upward of 12 to a series; 
nuchal organ very small, at anterior end of dorsal double series. 
Length of type, fully relaxed, 500 mm.; diameter, 8-10 mm.; introvert 
about 90 mm.; distance from head to nephridiopores, 130 mm.; to 
anus 140 mm.; to attachment of ventral retractors 215 mm.; to end 
of intestinal spiral 435 mm. (unusually extended for preserved speci- 
men). 
Description—The skin of preserved specimens is pale yellow or 
muddy brown. Except on the introvert it is closely beset with small, 
inconspicuous, roundish glands, on the order of 6 to 8 to each oblong 
triangle into which the skin is divided. These glands are sunken in 
the skin (which is smooth to touch) and are surrounded by the periph- 
_ eral portion of the subdermal coelomic pockets. Coelomic fluid enters 
these irregular spaces by way of the narrow intervals between the 
circular muscle bands. Stain forced into them indicates that the 
space just under the epidermis is independent for each rectangle. 
The annular and longitudinal grooves outlining the rectangles vary 
in depth with the inflation of the skin. The posterior end of speci- 
mens is likely to be very attenuate and pointed and the annuli con- 
spicuous. : 
The introvert is not especially well marked externally, except by 
the absence of the glands, and is the long portion characterized inter- 
nally by the sieve-like structure of longitudinal muscle layer. There 
are no hooks. 
None of the large specimens has the tentacle crown well enough 
expanded for a figure, and so it has been necessary to resort to a 
drawing of a small living specimen (length 70 mm.). The crown, 
while reminiscent of Phascolosoma gouldii, differs in having the ten- 
tacles of all the double rows, especially the dorsal, close together, with 
the result that the nuchal organ is almost rudimentary. There are 
12 of these double rows separated by 12 grooves: A dorsal double 
row (not more widely separated than the rest) reaching nearest 
to mouth; opposite it is a midventral; on each side, five laterals. 
Counting clockwise from the dorsal, double rows 2, 4, 6,8, 10, and 12 
