358 
THE VOYAGE OF H.M.S. CHALLENGER. 
A large example measures about 20 mm. in length, with a diameter at its widest 
part of fully 7 mm. 
The specimens have the usual dull whitish colour of the European Tmvisia forhesii, 
and appear minutely dotted under a lens from the glands. The number of segments is 
about the same as in the species just mentioned, viz., twenty-three, and in other respects 
the resemblance is close. In the Challenger form, however, the rings of the segments 
differ, and posteriorly the two last have a crenated margin dorsally, while the segment 
anterior to these also shows a few lateral pectinations. Moreover, the dorsal cirri are 
shorter, as are also the lateral caudal processes (PI. XLIII. fig. 10). 
The intestine is filled with dark sand, the coarse grains of which are 
covered over with numerous circular ova having a granular and probably adhesive 
investment for attaching them to the fragment, and tessellated here and there with 
smaller clear ovoid bodies ; while other sand-grains are hirsute with Diatoms. 
There is good reason, therefore, why this peculiar sand should be so utilised by the 
animals. 
In section the characteristic condition of the cuticular tissues of the genus is strongly 
marked in this form. When viewed laterally the surface seems to be formed by a 
closely arranged series of papillae (PL XXXVIa. fig. 1) with narrow pedicles, the whole 
resembling a series of closely arranged wine-glasses, for the narrow stem arises from an 
elevation of the tissues beneath. A careful examination, however, shows that the 
cuticle envelops each of these goblet-shaped papillae, being thickest in the interseptal 
regions, and forming the main part of the stem, which is thus translucent. The stems 
merge into the cuticular coating of the inner region of the hypoderm, which is fibro- 
granular. The external part of the hypoderm (constituting the bowl of the wine-glass) 
is coarsely granular and opaque, and apparently represents the outer or glandular part of 
the hypoderm split up into many divisions by the envelopes of cuticle. When viewed 
from the surface (PI. XXXVIa. fig. 2) the skin is thus made up of a vast series of some- 
what hexagonal facets. The spaces around the stems of the goblets probably subserve 
the same functions as the smaller and more numerous areolse in the hypoderm of other 
forms. The circular fibres beneath the hypoderm are not much developed. The 
longitudinal muscular layers seem to be nearly continuous. The ventral longitudinal are 
separated only by a narrow pedicle, to which is attached the somewhat triangular nerve- 
area, the latter having a straight superior border of firm tissue (sheath), to the outer 
angles of which the oblic[ue muscles are attached. The cords are rounded in transverse 
section. The central region of the body is occupied by voluminous folds of the 
alimentary canal. The nerve-area in this form thus slightly deviates from that in 
Travisia forhesii, which is situated between and somewhat above the oblique muscles, 
while other fibres are attached to the upper and outer curves of the region. 
In the structure of the skin this form somewhat approaches Travisia glandulosa, 
