236 



BULLETIN 140, UNITED STATES NATIONAL MUSEUM 



with 2 lateral lips, each bearing a conical tooth and with a pair 

 of very large papillae at the base. Buccal cavity or pharynx very 

 long, straight and tubular, extending to the level of the bicuspid 

 papillae. Nerve ring around esophagus near its origin. 



Male 5.7 to 12.2 mm. long by 240 to 255/* wide. According to 

 Seurat, in specimens 12.2 mm. long the cordons are 400/* long, the 

 bicuspid papillae are 430/* from the head end, and the tail is 420/* 

 long; according to Linstow, in specimens 5.7 mm. long the cordons 

 are 260/* long, the point of anastomosis is 72/* from the head, and the 

 tail length is 1/21 of the body length. Caudal alae hyaline, long 

 and wide, uniting anterior to caudal extremity. According to Seurat, 



Figs. 298-299. — Cosmocebhalus obvelatus. 298, a, Dorso-ventral view 

 and b, lateral view of an anterior end; c, female tail, ventral view. 

 After Seurat, 1919. 299, Male tail. After Linstow, 1877 



there are 3 preanal papillae on the right side and 4 on the left ; there 

 are 5 pairs of pedunculated postanal papillae and in addition there 

 are 5 small sessile papillae grouped between the 2 papillae of the 

 most posterior pair. Linstow described and figured 10 pairs of 

 papillae, of which 4 pairs are preanal and 6 pairs postanal, 1 pair 

 of the latter lying between the 2 papillae of another pair at the caudal 

 extremity (fig. 299). Spicules dissimilar and unequal, the right 

 thick and 130/* long, the left slender and 420/* long in small speci- 

 mens (Linstow), or 155/* and 540 /* long in large specimens (Seurat). 

 Female 9.7 to 20 mm. long by 300 to 380/*, wide. According to 

 Seurat, in a specimen 13.1 mm. long the cordons were 410/* long, the 

 bicuspid papillae 490/* from the head end, the vulva 2/5 of the total 

 body length, or 5.5 mm., from the head end, the anus (fig. 298c) 

 230/* from tail end, the eggs 36/* by 20/*, embryonated when oviposited. 

 According to Linstow, in a specimen 9.77 mm. long the cordons wer* 1 



