116 PROCEEDINGS OF THE NATIONAL MUSEUM vol.88 



Twenty-two (U.S.N.M. No. 8312) collected August 8, 1927, from 

 stomach of host; 10 to 36 mm. in length; pale pink to brick red; 

 necks in some translucent; intestine filled with black material. 



Subfamily Derogenetinae Odhner, 1927 

 Genus DEROGENES Luhe, 1900 



DEROGENES VARICUS (MuMtr) 



Plate 12, Figures 128-133 



Derogenes varicus (Miiller), Nicoll, Parasitology, vol. 3, p. 348, 1910. — Mantes, 

 Jouni. Parasit., vol. 13, p. 17, i925 ; Illinois Biol. Mou., vol. 10, no. 2, p. 103, 

 fig. 57, 1926.— FUHRMANN, Handb. Zool., vol. 2, p. 109, fig. 133, 1928. 



This species was found by Manter in 6 species of marine fishes. 

 Nicoll reports it from 19 species of British marine fishes. Although 

 recorded from a large number of hosts it is reported to occur only 

 in small numbers. 



Three specimens, one from each of three species of fishes, in the 

 collection from Woods Hole fishes appear to belong to this species. 

 The anatomy is incomplete!}' shown in each, but so far as it is shown 

 the agreement with this species is close. 



Hosts. — Common codfish {Gadus morrhua), flasher {Lobotes sur- 

 inamensis), fishingfrog {Lophius piscatoi^ius). 



Record of collections. — One (U.S.N.M. No. 8313), from common 

 codfish, collected December 13, 1894, associated with 52 specimens of 

 Hemiurus levinseni. Measurements in balsam: Length, 1.56 mm.; 

 breadth, 0.39 mm.; diameter of oral sucker, 0.19 mm., pharynx, 0.09 

 mm., ventral sucker, 0.33 mm.; ova, 0.054 by 0.033 imn., shells thick; 

 distance from anterior end to ventral sucker, 0.77 mm., from posterior 

 end to ventral sucker 0.63 mm. ; many of ova capped at one end. 



From flasher: One (U.S.N.M. No. 8314), collected September 1, 

 1910. Measurements in balsam : Length, 2.00 mm., breadth, at level of 

 ventral sucker, 0.53 mm., elsewhere from 0.28 to 0.42 mm. ; oral sucker, 

 length, 0.18 mm., breadth, 0.21 mm.; pharynx, length, 0.11 mm., 

 breadth, 0.10 mm.; ventral sucker, length, 0.36 mm., breadth, 0.39 

 mm. ; ova, average of ten, 0.051 by 0.036 mm., largest about 0.054 mm. 

 by 0.036 mm., shells thick; anterior end to ventral sucker, 0.98 mm. 

 There appears to be but one vitelline gland, posterior to the ovary on 

 the right side. The anterior end was very mobile in the living worm. 



From fishingfrog: One (U.S.N.M. No. 8315), collected August 30, 

 1920. Measurements in balsam: Length, 1.19 mm.; breadth, 0.36 

 mm.; diameter oral sucker, 0.14 mm., pharynx, 0.06 mm., ventral 

 sucker, 0.28 mm.; ova, average of six, 0.047 by 0.032 mm., largest 

 0.054 by 0.039, shells thick ; distance from anterior end to the ventral 

 sucker, 0.59 mm. ; few ova capped. 



