28 PEOCEEDINGS OF THE NATIOISIAL MUSEUM vol.70 



RECORD OF COLLECTIONS 



(U.S.N.M., Helm. Coll. 7871.) (Type.) 

 From Mergus serrator: 



1913, April 1. — One, scolex missing, length 75 mm., maximum 

 breadth 2.5. 



1913, April 15. — Fragments of strobiles, aggregating 165 mm., 

 longest 75, maximum breadth 3.75. 



1914, February 24. — About 30, half of them with scoleces. In one 

 strobile, measuring 130 mm. in length, the maximum breadth 

 was 2.25, and the diameter of the scolex was 0.21 ; in another, 

 measuring 295 mm. in length, the maximum breadth was 3, 

 and the diameter of the scolex 0.22. 



1914, February 28. — Twelve with scoleces, and an equal number 

 of fragments ; longest 153 mm., maximum breadth 4 mm. 



HYMENOLEPIS ARDEAE (Fuhrmann) 

 Figures 79-88 



Scolex. — Short, broad, rounded in front ; suckers circular, directed 

 forward; rostellum with single circle of 10 hooks, long dorsal and 

 short ventral roots, length about 0.033 mm. Diameter of scolex, in 

 balsam, 0.35 mm., of sucker 0.08 to 0.09 mm. 



Strohile. — Segments begin a short distance back of the scolex, 

 much broader than long throughout, flaring at basal border forming a 

 bluntly serrate outline on the lateral margins; genital pores uni- 

 lateral, near anterior end of the proglottis; length 125 mm., breadth 

 3 mm. or more. 



Male genitalia. — Cirrus short, cylindrical, bluntly tapering at apex, 

 thickly beset with short, slender spines ; length of cirrus about 0.090, 

 diameter 0.045, length of spines 0.007 mm. The cirrus-pouch in un- 

 ripe proglottides is subcylindrical, its inner end functioning as a 

 seminal vesicle, length 0.28, diameter 0.07 mm. ; in ripe proglottides 

 only the outer portion, into which the cirrus can be retracted, remains, 

 length 0.25, diameter 0,12 mm. A short vas deferens leads to an 

 inner, oval-elliptical seminal vesicle. The testes are three in number, 

 comparatively small, and lie side by side at the same level, a little 

 to the poral side of the median line. The inner seminal vesicle is 

 contiguous with the lateral margin of the lateral testis. 



Female genitalia. — The vagina opens on the ventral side of the 

 cirrus. It is a thin-walled, slender tube, except near the external 

 opening, where the walls are somewhat thickened. Its course is 

 parallel to the cirrus-pouch, near the ventral side of which it lies, on 

 the dorsal side of the excretory vessels. On the dorsal side of the 

 ovary and near the shell gland it ends in a small oval-elliptical semi- 



