ART. 7 CESTODE PARASITES OF BIRDS LINTON 47 



strobile, immature, which belong to a different species. While it is 

 not quite certain that these fragments belong to the same species as 

 that represented by the one scolex, there appears as yet to be no reason 

 for regarding them as specifically different. 



Scolex. — The rostellum (fig. 150) is short, its diameter nearly 

 equaling the length. It is surmounted by a single circle of about 

 18 hooks, which are short and strongly curved, about 0.010 mm. in 

 length (fig. 151). 



Strobile. — The neck, at first about the same breadth as the scolex, 

 grows slightly narrower a short distance behind the scolex. Dis- 

 tinct segments do not appear until about l.G mm. back of the scolex. 

 The proglottides are sharply outlined, and the lateral margins of 

 the strobile are distinctly serrate. Rudiments of genitalia have 

 made their appearance in the posterior proglottides. While rudi- 

 ments of the cirrus have not yet appeared, the indications are that 

 the genital pores are unilateral. 



A strobile, scolex missing, agrees with the fragment above de- 

 scribed. The segments at the anterior end are at the same stage 

 of development as those at the posterior end of the fragment with 

 scolex. The posterior segments are adult (fig. 152), but no ova have 

 yet appeared. There are three relatively large testes, two antiporal 

 and one poral. The antiporal testes are contig-uous, one being situ- 

 ated at the antero-median border of the other. The ovary is lobed, 

 the vitelline gland, small, subtriangular in outline, and compact. 

 Genital pores unilateral; cirrus not seen extruded. It appears to 

 be short, the principal part of the cirrus-pouch acting as a seminal 

 vesicle. In dorso-ventral view the cirrus-pouch appears to be oblong- 

 elliptical in outline. In other fragments of strobiles, apparently 

 belonging to the same species, seen in marginal view, the cirrus- 

 pouch as a whole is much curved, in some cases S-shaped. 



Dimensions of fragment of strobile with scolex : Length 12 mm. ; 

 diameter of scolex 0.18, of sucker, 0.08; length of rostellum 0.06, 

 length 0.054; length of hooks 0.010; length of last segment 0.08, 

 breadth 0.36. 



Dimensions of strobile, scolex missing: Length 54 mm.; length of 

 anterior segments 0.08, breadth 0.28; length of median segments 

 0.11, breadth 1.15; length of posterior segments 0.16; breadth 1.22. 



This material belongs to the lot collected by Vinal N. Edwards on 

 November 4, 1913. 



(2) A single specimen collected from Marila marila., August 23, 

 1887 (U.S.N.M., Helm. Coll. 7883) is here recorded. But little more 

 than an outline of the somewhat compressed scolex can be made out in 

 the mounted specimen ; even the suckers are too faintly shown to per- 

 mit measurement. They have been added to the camera lucida 

 sketch (fig. 148) from a memorandum sketch made at the time of 



