PARASITES OF FISHES OF THE WOODS HOLE REGION. 445 



CBSTODES. 



2. Larvid ceslurles (Srolf.t: pohjmorphtix Dujardin) . Small. Free in intestine. Aujr. 2 and 3, 1S99; 



July 9, 1900; numerous. For account of similar forms, see 4, pp. 789-792. 



3. Dibolhrium !>p. Young and larva. .Intestines. Juh- 9, 1900; a yomig specimen with aliout a dozen 



segments, very active; resembles Diholhriiim piinctatum (2, p. 731). Also a flask-shajTed larva 

 2 mm. in length when at rest, but capable of stretching to much greater length. 



4. Rhynchohothrxum iinjKirigpUu: Linton. Encysted. 4, p. SOO. 



5. Rhynchohothrium speciosum Linton. Encysted. 4, p. 802. 



6. Ehynchobothrium bulbifer 'Linton. [PI. .x.xi, fig. 2-14.] Aug. 2, 1899. Encysted in muscles of back. 



TKE>I.\TODES. 



7. Distoiimm vileVmvm Linton. See 7, p. 290, pi. xxxyu, figs. 38, 39. Aug. 2, 1899; July 9, 1900. 



A few small distomes which agree with this species in essential t'haracters were seen on the two 

 dates given. These were very active anil a.'^sumed such a great variety of shapes that they can not l)e 

 characterized briefly. AVithin the space of a second or two the length may change from 0.7 nun., for 

 example, to three times that length or more. The vitellaria are opaque dead-white, other portions 

 translucent bluish-white. Ova, few, rather large, dimensions the same as those given for 7). riMJoxum. 

 In death the worms are cylindrical, acetabulum prominent, neck sometimes reflexed. This remark 

 applies to those distomes which in this paper are referred to this species. The characteristic subangular 

 appearance of the vitellaria is not evident in the living specimens. 



8. Disloinum appendiciilriliim Rudolphi. Aug. 2, 1S99; few. Aug. 12, 1899; ."iO. 7, ]i. 2S9, pi. .\xxvi, 



figs. 25, 26. 

 These appendiculate distomes agree exactly with those from the flounder, which were referred 

 witli much hesitation to D. appendicvlntum. 



Gymnosarda pelamys, fkrini Bonito. 

 I. TrisUiiuum here Verrill. Gills. 6, p. ,509, pi. xi., figs. 7, 8. 



Thunnus thynnus, Jfursr Mm-ki-reJ. 



I had no opportunity to examine this fish for parasites until the summer of 1900. On July IH the 

 head (weight, 184 pounds) and viscera of a specimen, taken in a fish trap at IVIenemsha Bight, on 

 the 14th were brought to Woods Hi>le. The only indication of the character of the food wa.-j the jaw 

 of a s(|uid in the intestine. The only entozoa were two distomes in the stomadi. 



TUKM-VrollES. 



1. l>ixlo>nu)n clavulum Rudolphi. 



Larger specimen 17 mm. long and 7 mm. in greatest diameter. The smaller was I-t mm. and 

 .5 nun. in the corresponding dimensions. See 6, jip. 539-540, pi. liii, figs. 8-U. 



Sarda sarda, Uoiiilo. 



The stomachs of bonitos which I liave examined have usually lieen empty, Ijut occasionally I 



have found fragments of fish and squid in the alimentary canal. See also 7, pp. 277-278. 



N'KM.\TOnE'i. 



1. ,4,sv»r«sp. [PI. v, figs. 37-10.] 



Eight in stomach of one fish July 15, 1899. Length of male, 25 nnii.; of female, 40 nnn. Anal 

 papilla' much as in .4. habena. On each side there are 5 small postanal pai>ill!e and 10 small preceded 

 by at least 20 larger preanal papillje. The jaws are prominent and two-toothed. The cuticle was 

 imperfect in most of the specimens, as if it had been attacked by the digestive fiuids. 



