FISH ENTOZOA FROM YELLOWSTONE PARK. ' 555 



ACANTHOCEPHALA. 



EOHINOHIIYNCHL'S Ul.OBULOSU.s Rud. 



[Plate 65, Figs. HI, H2.] 



A fragment of an echinorhyiicbus from a trout {Salmo myl-iss) 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 O.IG mm.; length of hooks, 0.05 to 

 O.OG mm. There are about ten rows of hooks and about tbe 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 lemnisci 

 were not clearly made out, but they appear to be shorter than the 

 sheath. 



ECHINORHYNCUTTS TUBEROSUS Zedei'. 



[Plate 66, Figs. ,33-39; Plate 67, Fig. 40.] 



Zeder, Naturg., 163; Rndolpbi, Entoz. Hist., ii, 257; Synops.,65 and 312; West- 

 ruinb, Acanthoceph., 9; Ciepliu, Obs., 26; Wieginann's Arcb., 1846, 150, 

 152, 154, and 155; Dujardin, Hist. Nat, des Helmiutb., .538; Diesing, Syst. 

 Helmintb., ii, 33; Revision der Rbyngodeen, 29. 



Proboscis short, clavate, or subglobose, with about three series of 

 hooks; about six large hooks iu 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 n)ales sometimes equal to more than one-half the length 

 of the body. Body elongated, attenuate at each end. Males with 

 cojiulatory bursa. Length of males from 4 to mm., of females from 

 10 to 1") mm. 



Habitat: Catostomus ardens, Lenciscus atrarm.s, intestiiu?; July 28, 

 1800; Heart Lake, Wyoming. 



I refer to this S])ecies a lot of 7.5 echinorhynchi from the intestine of 

 tha ^nckev {Catostomus ardens). Eight large fish were examined and 

 echinorhynchi were, found in most of them. I also refer to the same 

 species a single specimen from the intestine of a chub {Lenciscus atra- 

 rius). Th» majority of th« specimen* of the first lot wer« translucent 



