FISH ENTOZOA FROM YELLOWSTONE PARK. 555 
ACANTHOCEPHALA. 
ECHINORHUYNCHUS GLOBULOSUS Rud. 
’ 
- [Plate 65, Figs. 31, 32.] 
A fragment of an echinorhynchus from a trout (Salmo mykiss) col- 
lected by Dr. Jordan in Yellowstone Lake, in September, 1889, appears 
to belong to this species, or at least near it. The fragment is the 
anterior end of a female broken a short distance back of the proboscis 
sheath. The length of the fragment is 3 mm.; the length of the 
proboscis is 0.6, and of the sheath 1.2 mm.; the diameter of the 
proboscis at base is 0.27, at apex 0.16 mm.; length of hooks, 0.05 to 
0.06 mm. There are about ten rows of hooks and about the same 
number in each spiral visible on a side, and about sixteen hooks in a 
vertical row. The specimen was put in glycerin to study, and the pecul- 
iar shape of the proboscis may be in part due to a collapse of its walls. 
The proboscis is cylindrical at base, tapers abruptly about the middle, 
and becomes cylindrical again towards the apex. The hooks on the 
slender part of the proboscis were somewhat distorted. This feature 
appears in the two upper right-hand hooks in Fig. 32. The lemnisei 
were not clearly made out, but they appear to be shorter than the 
sheath. 
ECHINORHYNCHUS TUBEROSUS Zeder. 
[Plate 66, Figs. 55-39; Plate 67, Fig. 40.] 
Zeder, Naturg., 163; Rudolphi, Entoz. Hist., 11, 257; Synops., 65 and 312; West- 
rumb, Acanthoceph., 9; Creplin, Obs., 26; Wiegmann’s Arch., 1846, 150, 
152, 154, and 155; Dujardin, Hist. Nat. des Helminth., 538; Diesing, Syst. 
Helminth., 11, 33; Revision der Rhyngodeen, 29. 
Proboscis short, clavate, or subglobose, with about three series of 
hooks; about six large hooks in outer series, hooks in other series 
diminishing in size and number toward base of proboscis. Hooks 
long, slender, recurved, but with slight outward curve toward the 
point. No neck. Proboscis sheath short. Lemnisci very long and 
slender, in the males sometimes equal to more than one-half the length 
of the body. Body elongated, attenuate at each end. Males with 
copulatory bursa. Length of males from 4 to 9 mm., of females from 
10 to 15 mm. 
Habitat: Catostomus ardens, Leuciscus atrarius, intestine; July 28, 
1890; Heart Lake, Wyoming. 
I refer to this species a lot of 75 echinorhynchi from the intestine of 
the sucker (Catostomus ardens). Wight large fish were examined and 
echinorhynchi were found in most of them. JI also refer to the same 
species a single specimen from the intestine of a chub (Leuciscus atra-— 
rius). The majority of the specimens of the first lot were translucent 
