528 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
proboscis sheath, 0.8 mm ; diameter of sheath, 0.22 mm ; diameter of probos- 
cis, 0.2 mm ; length of hooks, 0.046 mm . 
On September 6, 1887, I examined ten or twelve specimens of scup. 
The entozoa found were a few Nematods and Cestod cysts and one 
femal q Echinorhynchus. all in the body cavity, attached to the peritoneum 
where they were surrounded by a thin membranous Covering. 
The specimen is about 7 mm in length and .4 mm in diameter. The body 
cavity is filled with globular masses not yet differentiated into ova. 
The outline of the proboscis and the arrangement and number of the 
hooks correspond with E. acus. There is, however, this peculiarity : 
the hooks are surrounded at the base by a raised collar somewhat as in 
E. thecatus. 
Echinorhynchus THECATUS, sp. DOV. 
[Plate n, figs. 12-22.] 
The following description is based on alcoholic specimens collected by 
Prof. S. E. Meek, at Fulton Market, New York, and received by me 
October 20, 1886. There were eighty-seven specimens in the lot, the 
longest females about 20 mm in length, the shortest males about 5 mm . 
Body cylindrical, usually arcuate, smooth, tapering slightly for a 
.short distance at anterior end, but little tapering posteriorly, sometimes 
slightly enlarged and rounded at posterior end. Neck short, conical, 
unarmed. Proboscis fusiform, often oblique to axis of body, with about 
twelve series of hooks, about six visible on a side in a single spiral. 
Ventral hooks strongly recurved ; dorsal, arcuate, all becoming smaller 
near base of proboscis. Each hook surrounded by a thin, transparent 
sheath, which incloses the base and about half the length of the 
hook. Proboscis sheath longer than proboscis. Lemnisci very long, 
slender, reaching to the second testis in the male, but often doubled on 
themselves. Testes two, median, contiguous, followed by a botryoidal 
mass of about six prostatic sacs. These are succeeded by a large 
ejaculatory duct. The bursa was retracted in all cases, but could be 
plainly seen through the wails of the body. 
The following measurements of two alcoholic specimens, a male-and 
female, slightly compressed, are given for purposes of comparison : 
Measurements. 
? 
d 
I J0Dgth r - rir _ - Tr T - - - - . 
mm. 
18. 00 
0.60 
mm. 
12.00 
0. 60 
Diameter of body, anterior 
Greatest diameter ...................................... 
1. 40 
1.30 
0. 54 
Diampt.er npa,r posterior p.nr'l ... 
0. 90 
Length of nfip.lr .. 
0. 26 
0.26 
Diamp, ter of prohoseis a.pev .... 
0. 20 
0. 22 
Diameter of proboscis, middle - 
0.30 
0. 30 
Diameter of proboscis, base 
0. 26 
0.23 
Length of prohoseis . 
1. 00 
0. 80 
Length of sheath 
2. 45 
] . 90 
Diameter of sheath 
0. 38 
0. 36 
Length of lemniscus 
5. 00 
4. 20 
Diameter of lemniscus 
0.08 
0. 08 
