982 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
When seen in prepared sections the ocelli appear to be highly developed, with well-marked 
lens and pigment cup. They are situated for the most part in the glandular portion of cutis immediately 
beneath the basement membrane of the integument, although a few are scattered in the deeper 
cephalic musculature. They extend posteriorly as far as the brain commissures, both of which occur 
in a single transverse section. 
Color . — Definite color in life unknown, for after short preservation the body loses its general color, 
although it retains certain definite and characteristic markings. These markings consist of a series of 
narrow but sharply marked rings situated at fairly regular intervals throughout the whole length of 
the body (pi. 1, figs. 4, 5). After preservation the general ground-color of the body is very pale or 
whitish, while the rings are reddish brown and are always conspicuous from above, although they are 
often wanting on the ventral surface. The most anterior ring or rather transverse marking, is situated 
on the snout a short distance in front of the transverse groove and is incomplete, appearing on the 
dorsal surface only, and not extending laterally even as far as the groups of ocelli ; the second is situated 
exactly in the region of the mouth and is interrupted on the ventral surface by the mouth opening; 
do 
' icm 
Fig. i.—Tseniosoma cingulatum sp. nov. Transverse section of body through posterior 
end of esophageal region, showing the thick layer of circular muscles (icm) forming 
a sphincter about the posterior end of the esophagus (e) ; (a) groove of cells similar 
to those of stomach; (do) dorsal blood vessel; (rc) rhynchocoel; (el) esophageal 
blood lacunae; (In) lateral nerve. Other reference letters as in fig. 1. x 30. 
then follow an irregular series of rings, some of which are complete while others are represented 
merely by transverse markings on the dorsal surface (pi. 1, fig. 5). All the rings are very narrow, 
but some are much finer than others and are indicated only by a 'few scattered dots. 
In one of the two specimens collected the rings were for the most part complete, but were narrower 
on the ventral surface than dorsally, while in the other they were represented as transverse markings 
mainly confined to the dorsal surface. In the former specimen the body was contracted and the rings 
were separated from each other by considerably less than the body diameter (pi. 1 , fig. 5), while in 
the other specimen, which was preserved in a fully extended state, the rings in the intestinal region 
were often separated by a space equal to three to five times the diameter of the body (pi. 1, fig. 4). 
After having been preserved for a year in alcohol the specimens retain only faint indications of 
their original markings. 
Proboscis . — Proboscis sheath short, extending only to anterior end of the intestinal region; com- 
posed of outer circular and inner longitudinal muscles (fig. 6). Proboscis small and weak, attached 
to tissues of head immediately anterior to brain commissures. Muscular walls of proboscis consisting 
