TREMATODES FROM FISHES — LINTON 



167 



seen in only one specimen, appears to lie in front and to the right 

 of the cirrus-pouch, and to open at the genital pore. All of the 

 specimens are more or less distorted by compression. The ova are 

 numerous, elliptical, from 0.033 by 0.018 mm. to 0.037 by 0.021 mm. 

 The excretory pore and a small portion of the excretory vessel are 

 visible in one of the mounted specimens, but little can be distin- 

 guished on account of the dense mass of ova with which the posterior 

 end of the body is filled. 



Table 39. — Measurements of four specimens of Deretrema fusillus in balsam 



Measurement 



Length. 



Breadth 



Oral sucker, length 



Oral sucker, breadth-. 



Pharynx, length 



Pharynx, breadth 



Ventral sucker, length 



Ventral sucker, breadth. 



Posterior edge of ventral sucker to anterior end 



Mm. 

 1.15 

 .68 

 .12 

 .11 

 .11 

 .10 

 .35 

 .25 

 .63 



Mm. 

 1.36 

 .68 

 .11 

 .17 

 .11 

 .11 

 .35 

 .28 

 .87 



Aim. 



2.10 

 .84 

 .28 

 .32 

 .14 

 .14 

 .42 

 .36 



1.10 



Mm. 

 2.87 

 1.12 

 .27 

 .32 

 .22 

 .22 

 .42 

 .35 

 1.27 



' No. 3 ventral view, others lateral view. 



Host. — Sharp-filmed flyingfish {Exocoetus volifans). 

 Record of collections. — One, collected July 16, 1910. Two, collected 

 August 9, 1910. One (U.S.N.M. No. 8403), collected August 27, 1928. 



Genus SIPHODERA Linton, 1910 



SIPHODERA VINALEDWARDSII (Linton) 



Monostomum vinaledwardsii Linton, Bull. U. S. Fish Comm. for 1899, p. 470, 



figs. 373-376, 1901. 

 Monostomum vinal-edwardsii Linton, Bull. U. S. Bur. Fish., vol. 24, pp. 379, 410, 



1905 ; Proc. U. S. Nat. Mus., vol. 33, p. 118, fig. 97, 1907. 

 Siphodera vinaledwardsii (Linton), Carnegie Inst. Washington Publ. 133, p. 74, 



figs. 208, 209a, 1910.— Manter, Illinois Biol. Mon., vol. 10, pp. 107-110, figs. 



80-83, 1926. 



Hosts. — Toadfish {Opsanus tau) and alewife {Poinolohus pseudo- 

 harengus) . 



Record of collections. — No special search for this trematode has 

 been made at Woods Hole since the first description of the species was 

 published. I have record of collections from toadfish on four dates in 

 August and one in October, in four different years, from 1903 to 1914 ; 

 17, from eight fishes; one to five worms in each. (U.S.N.M. No. 

 8404). 



One, from alewife, collected July 26, 1906; length of living speci- 

 men, 2.52 mm., breadth, 1.12 mm. ; ova, 0.021 by 0.010 mm. 



