526 REPORT OF COMMISSIONER OF FISH AND FISHERIES, 
The proboscis in this species is, as a rule, linear, but sometimes is 
enlarged slightly at the base, and sometimes increases in size a little 
towards the apex. There are about 10 series of hooks visible on a side, 
or 20 in all, and 16 hooks, more or less, in a longitudinal row. The 
hooks are about .06 mm iu length, stout, and strongly recurved. The 
proboscis is much smaller than the anterior part of the body, and is 
very commonly inclined obliquely or even at right angles to the axis of 
the body. In the latter case the body is prominently shouldered an- 
teriorly. The proboscides were observed in some cases simply retracted, 
in others partly or completely inverted. The neck is so short as to be 
invisible when there is the slightest invagination of the body at the base 
of the proboscis. In some of the specimens from Limanda ferruginea 
a short, conical neck was seen. The proboscis sheath is one and a half 
to two times as long as the proboscis, and the lemnisci usually a little 
longer than the sheath. 
The two testes are oblong, situated a little back of or near the middle 
of the body, aud separated from each other by an interval somewhat 
less than the length of a single testis. They are usually distant from 
the remainder of the genitalia, which consist of a moniliform chain of 
about six prostatic glands and an elongated ejaculatory sac. 
These parasites are abundant, especially in P. americanus , where the 
intestine is sometimes distended with them. In cases where several 
fish were examined at the same time, e. g. in No. 13, where 17 flounders 
were examined, by far the greater number of parasites obtained were 
found in the intestines of two or three of the hosts. 
The following notes on color, etc., were made from observations on 
lot 13, from P. americanus: Color in general light orange-yellow; many, 
cream-yellow merging into light orange-yellow, with one or two spots 
of orange. In the lot of 116 Echinorhynchi three or four were a light 
lemon-yellow, one greenish-yellow, and one prange-yellow ; one light 
orange iu front, posterior half cream-color. Some were plump, aud 
others were flat, thin, and flaccid. Some were curled up and transversely 
wrinkled, others elongated and straight. Some of the straight, flat, 
thin ones marked with transverse opaque blotches. 
Upon being placed in fresh water for a short time these ‘worms be- 
came distended,* while the color changed to light-cream, with a faint 
tinge of orange or lemon-yellow. One specimen, which in sea water 
was cylindrical and measured 20 imn , after lying in fresh water for 1 
hour measured 48 lum , and 55 mm iu 1J hours more. Another, which in 
sea water was flat and thin and 26 mm in length, after being in fresh water 
for 1 hour measured 30 mm in length, otherwise but little changed except 
that it was plumper and the proboscis, which at first was retracted, 
afterwards protruded obliquely, A straight, thin, and flat specimen, 
25 mm j u length, was placed in Perenyi’s fluid. In half a minute it 
shrunk to 12 mm , and was rather plump, rugose, and bluish-white in 
r U. S. F. C. Report for 1886, page 508, plate v, figs. 10, 11. 
