978 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
has indisputable priority over the name Eupolia, although the latter is still retained by most European 
writers. The fact that Stimpson in 1857 a , in establishing his new genus Tseniosoma, in addition to 
giving a satisfactory generic diagnosis, specially mentioned Borlasia quinquelineata Quoy & Gaimard 
as a typical species of the genus leaves no valid excuse for ignoring this name and adopting that given 
by Hubrecht thirty years later. Furthermore, Stimpson in the same paper describes as new species two 
forms, T. septemlineatum and T sequale ( — T quinquelineatum) both of which are typical representatives 
of the genus. Although Stimpson’ s generic diagnosis is brief it is accurate, and its brevity is justified 
by the citation of a well-known typical species. • 
The species belonging to this genus show a remarkable specific variation in the general shape and 
size of the body. Some are characterized by extremely long, slender, flattened, and much-twisted 
bodies, while others are short, thick, and cylindrical. In nearly all the species, however, the head in 
life is rounded in front and is sharply marked off from the parts immediately following by lateral 
constrictions. Horizontal furrows are wanting, but small, oblique or transverse grooves are usually 
present on the head. In strong contraction the posterior portion of the head becomes greatly swollen 
and the snout is withdrawn into it, the . anterior end of the body becoming large and abruptly 
truncated. 
Proboscis sheath and proboscis short, seldom reaching more than one-third the length of body. 
Proboscis opening subterminal, minute. Mouth situated on the ventral surface immediately behind 
the ganglia . 
Muscular layers of body composed of a thick outer longitudinal, a circular, and a less thickened 
inner longitudinal layer. Outside the muscular layers is a well developed cutis, composed of a thick 
inner layer of connective tissue, and an outer layer of glandular tissue. External epithelium thin as 
compared with the other layers of the body, though the basement layer separating it from the cutis is 
usually well developed. Musculature of proboscis consists of an inner longitudinal and an outer 
circular muscular layer; consequently muscular crosses are wanting. Cephalic glands enormously 
developed, stretching backward on all sides beyond the brain, and often reaching some distance into 
the esophageal region. 
Lateral nerves situated immediately outside circular muscular layer. Ocelli usually present in 
great numbers, though very small. There are three longitudinal blood vessels. 
These worms are sluggish in their habits, are unable to swim, and usually show great irregularities 
in the diameter of the body. They often twist their bodies in sharp coils or in knots, or lie tangled 
together in lumps. All species are extremely contractile. 
Taeniosoma univittatum sp. nov. 
(PI. i, figs. 1-3; text cuts 1, 2.) 
This species is represented in the collection by four well-preserved specimens which were dredged 
from depths between 127 and 178 fathoms. 
The specimens bear a close external resemblance to those of a species which Isler, & in 1900, 
described from the Indian Ocean (Ceylon) under the nam e Eupolia unistriata. The next year, and 
evidently written while Isler’s paper was in press, Punnett c gave a description of a very similar species, 
also collected in the Indian Ocean (Maidive Islands), to which he gave a name identical with that 
which Isler gave to his species, viz, Eupolia unistriata. Isler’s specimens were yellowish-white with 
a narrow longitudinal stripe of olive green, while Punnett’s specimens were white with a similar 
narrow stripe of black. Those described by Isler possessed numerous ocelli; Punnett does not state 
in his description whether such sense organs were present in his specimens, but he writes me that 
they are as well developed as in T. melanogrammum. The two forms, to which the one specific name 
was given by both of these investigators, are evidently very closely related, if not identical. Although 
very similar to them in form and coloration of body, the species herein described, Tseniosoma univit- 
tatum, differs in the total absence of ocelli and in minor anatomical details. 
From Timiosoma hemprichi (Ehrenberg) and T. mediolineatum (Burger), both of which possess a 
median ventral as well as a median dorsal brown or blackish stripe, the present species differs con- 
spicuously in the possession of a dorsal stripe only. 
oProc. Ac. Nat. Sci. Phila., 1857, 162. 
l> Zool. Anzeiger, XXIII, 1900, p. 178. 
c Gardiner’s Fauna and Geography of the Maidive and Laccadive Archipelagoes, Vol. 1. p. 106, pi. iv, fig. 4, 1901. 
