*s 
ake 
94 _ NOTES ON AVIAN ENTOZOA—LINTON. 
Body divided into a shorter anterior and a longer posterior part by a _ 
profound constriction. Anterior part of body subglobose, variable, — 
aperture transverse; posterior cylindrical, curved, slightly attenuate. 
Reproductive aperture terminal, circular, surrounded by an ample mus- — 
cular border and with a central, obconical, protractile part. ' 
Length, 3.7 millimeters. ; 
The foregoing is a brief synopsis of the superficial characters of my — 
_ specimens and differsin some particulars from the descriptions of H. varia-_ 
bile given by Diesing and others. For example, the species is usually — 
described as being bilabiate and gaping at the apex. My specimensare | 
so much contracted that this character, while not contradicted, is not | 
manitest. 
This peculiar entozoan has been found infesting a number of species | 
of raptorial birds. Von Linstow has noted its occurrence in twenty- 
four species distributed among the following genera: Nyctale, Ulula, 
Agolius, Surnia, Bubo, Strix, Circus, Pernis, Buteo, Aquila, Cireaétos, 
Pandion, and Falco. (Compend. Helminth.) ; 
The following account is based on four specimens from the intestines — 
of Circus cyaneus var. hudsonius collected pear Yellowstone Lake, Wy- 
oming, August, 1890. The specimens when studied were all alcoholic, 
no observations having been made on the living worms. ; 
Two of the specimens furnished the following measurements: 
ws 
ike Nee | 
mm. | mm 
—— aioe ss eres was F< se 
Wel Wi) ta die eae So caoe nonin Soecnogacgsoc: 3.70 | 3.60 
Le sngth of anterior, subglobular part..-..- 60 | .80 
Diameter of anterior part apne gesotes Terbone -90 | .80 
Diameter of posterior part, MediaNn...-s-.0e0 -70| .80 
Diameter of posterior end.....-.........---. -40 | .45 
Diameter of posterior aperture..-.......--- Saleh elics 
The ova measure 0.09 millimeter in length ‘and 0. 065 millimeter in 
breadth. . 
The bodies of all the specimens are bent abruptly at the constric-— 
tion and the posterior portion is also more or less curved. From the 
examination of a series of sections it was ascertained that the anterior | 
portion is bent abruptly backwards so that its dorsal region approx- 
imates the dorsal region of the posterior part. This is effected by some 
strong fascicles of longitudinal muscles which have their principal de- 
velopment in the dorsal and dorso-lateral regions of the body. 
Anatomy.—The following observations on the anatomy of this species 
are based on a series of longitudinal sections made parallel to a dorso- 
ventral plane, and stained with borax carmine. 
In the anterior, subglobular division of the body there are three — | 
museular organs placed near together (Fig. 29, m. ph. s.) which repre- 
sent the mouth, pharynx, and ventral sucker. The first and third of 
these appear, 1n the sections, to cpen into the interior of the mass, since | 
that part of the body is much folded together and contracted. This part_ 
of the body appears to be capable of expanding into a comparatively — ; 
large suctorial or, more properly, absorbing surface. | 
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