234 BULLETIN 140, UNITED STATES NATIONAL MUSEUM 



subcylindrical, attenuated posteriorly, slightly eurved, densely stri- 

 ated transversely. Two lateral alae with numerous transverse stria- 

 tions in anterior half of body. Two prominent cervical papillae just 

 posterior to cordons. Buccal cavity or pharynx short and slender. 

 Esophagus 1/3 as long as body and half as wide as body. 



Male unknown. 



Female 15 mm. long by 300[jl wide. Tail obliquely truncate and 

 pointed. Vulva near middle of body; judging from the length of 

 the esophagus and Molin's figure (fig. 296 a), the vulva is just ante- 

 rior to middle of body ; it has 2 prominent lips. " Oviduct " passes 

 posteriorly towards caudal extremity. Anus (fig. 296 c) a short 

 distance anterior to caudal apex. 



Life history. — Unknown; probably involves intermediate stages 

 in other hosts. 



Distribution. — Europe (Italy (Padua)). 



Fig. 29G. — Cosmocephalus dibsingi. a, Anterior and middle parts of worm, 



SHOWING POSITION OF VULVA ; b, ANTERIOR END ; C, FEMALE TAIL. AFTER MOLIN, 



1861 



COSMOCEPHALUS ADUNCUS (Creplin, 1846) Yorke and Maplestone, 1926 



Synonyms. — Spiroptera adunca Creplin, 1846 ; Dispharagus adun- 

 cus (Creplin, 1846) Molin, 1860c. 



Hosts. — Primary: Colymbus septentrionalis, Larus argentatus, L. 

 canus, L. glaucus, L. mari?ius, L. medius, L. ridibundus, Podiceps 

 auritus; secondary : Unknown. 



Location. — Esophagus. 



Morphology. — Cosmocephalus (p. 233) : Mouth (fig. 297tf) Avith 

 2 lips. No cephalic papillae observed. Cordons scalloped on inner 

 edge as in C. obvelatus, comparatively short, their length about 1.5 

 times the width of the body at the level of the cordons. Cervical 

 papillae small and bicuspid, a short distance posterior to the 

 cordons. 



Male 8.6 to 11 mm. long by 280 to 300^ wide. Caudal extremity 

 (fig. 297 b) obtuse. Caudal alae wide. Nine pairs of long, pedun- 

 culated papillae, of which 4 are preanal and 5 postanal. Spicules 

 180[i long and 700/* long, the longer with a barb at its distal end. 



Female 10.5 to 15 mm. long by 290 to 400/* wide. Tail 10/732 of 

 total body length, with a sucker-like enlargement at the end. Vulva 



