. Bulletin - United States National Museum. Science. NEMATODE PARASITES OF BIRDS 39 SYNGAMUS PARVUS Chapin, 1925 Host.—Nucifraga caryocatactes. Location.—Trachea. Morphology.—Syngamus (p. 34) : Similar in general shape (fig. 41) to S. trachea, but much smaller and differing in secondary sexual characters of male. Male about mm. long by 220/x, wide, cylindrical, with neck region slightly constricted. Buccal capsule heavily chitinized, 178/x in depth, 207^ in its greatest inside diameter; walls 29/*. thick. Buc- cal teeth and circumoral papillae as in S. trachea. Esophagus about 326/x long;
. Bulletin - United States National Museum. Science. NEMATODE PARASITES OF BIRDS 39 SYNGAMUS PARVUS Chapin, 1925 Host.—Nucifraga caryocatactes. Location.—Trachea. Morphology.—Syngamus (p. 34) : Similar in general shape (fig. 41) to S. trachea, but much smaller and differing in secondary sexual characters of male. Male about mm. long by 220/x, wide, cylindrical, with neck region slightly constricted. Buccal capsule heavily chitinized, 178/x in depth, 207^ in its greatest inside diameter; walls 29/*. thick. Buc- cal teeth and circumoral papillae as in S. trachea. Esophagus about 326/x long; nerve ring and excretory pore not located. Bursa (fig. 43) 350/u. in diameter; ventral rays short, stout, and approximate; lateral rays stout; medio-lateral ray very stout; externo-lateral ray arising from the side of the medio-lateral; postero-lateral ray slender in comparison with the other two. Externo-dorsal ray more. Pigs. 41-43.—Syngamus parvus. 41, Outline of pair. 42, Spic- ules. 43, Dorsal portion of male bursa. After Chapin, 1925 slender and parallel than postero-lateral; dorsal trunk bifurcated near tip, each bifurcation simple. Spicules (fig. 42) short, about 49/x, similar in shape to those of S. trachea. Female about mm. long by 65Gyt maximum width; width just posterior to head 350^. Buccal capsule 300^ in depth, 440^ in aver- age diameter. Buccal teeth as in S. trachea; nerve ring and ex- cretory pore not located. Esophagus short and thick. Vulva in gravid worm dividing total length into ratio as 1; uterine coils extending posteriorly to mm. from extremity (x in fig. 41) ; anus subterminal; tip of tail very blunt. Eggs 74^ by 44^, not yet segmenting in uterus. Life history.—Unknown; probably similar to that of S. trachea (p. 36). Distribution.—Not given. (Host occurs in Europe.) SYNGAMUS GRACILIS Chapin. 1925 Synonym.—Syngamus trachealis Weidman (part), Fox, 1923. Host.—Corvus brachyrhynchos. Location.— Please note that thes
Size: 2480px × 1008px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorun, bookcentury1800, bookdecade1870, booksubjectscience
