PARASITES OF FISHES OF THE WOODS HOLE REGION. 425 



SUMMARY OF FISH PARASITES ARRANGED UNDER THEIR HOSTS. 

 Mustelus canis, SiniHith llaij-jhli. 



KOOI). 



Tlie alimentary canals usually contain crabs ( PaiKi/jiiis, Pliili/iiiiirjiii.i, Cmn-i'r, Lihlnla, etc. ). Squid, 

 annelids, and fish have also been noted. 



NEMATODICS. 



1. Ascark sp. [PI. ix, fig. 90.] 



Two imperfect specimens in U. S. National JIuseum collection apparently removed from peritoneal 

 capsules. Dimensions in millimeters: Length, 23; diameter of head, 0.12; maximum diameter a little 

 back of middle, 0.4.5; distance of anal aperture from posterior end, 0.1.5. Head with three short lips, 

 two bluntly angled, the third rounded. Body transver.sely rugose; posterior end bluntly rounded 

 with a mucronate tiji which is conical and wrinkled. 



CESTOnES. 



2. Diluillirlniii sp. .S])iral valve. 5, p. 433. 



3. Oilliobnlhriuiii irrt(ciHa(io;i Rudolphi. Spiral valve. 1, pp. 476— f7!l, pi. iv, figs. 1-8. 2, pp. 810-812. 



5, i>. 447, pi. xx.xiv, figs. 05, 7. 7, p. 270. Aug. 14, 1899; from two hosts, 2.5 large, 9 small. 

 Aug. 28, 1899; froiu one host, 8. July 18, 1900; from one host, 63. 

 Kipe proglottides noticed on one occasion upon which apertures for discharge of ova had devel- 

 oped. These were arranged along the median line of one of the flat surfaces and numljered about five 

 in most cases, although as many as eight were counted. When the proglottis was viewed from the 

 margin these apertures were seen to be slightly projecting. [PI. xxvr, fig. 289, <i and h.] 



4. OiUioholhrium eschrichlii Be.nedtin. Spiral valve. 2, pp. 812-816, pi. vii, figs. 5-12. 5, [1.447. Aug. 



14, 1899, 1. 



5. Rhyiichobolhrium lomentaceum Diesing. Spiral valve. 2, pp. 845-847, pi. xiii, figs. 1-3. 



6. liynrliiihiithrbiin bulhifer Linton. Spiral valve. I [A*, tenuicolle Rudolphi], jjp. 486-4.S8, pi. v, fi^.s. 



17, 18. 2, pp. 82.5-829, pi. x, figs. 8, 9, and pi. xi, figs. 1, 2. 5, p. 448. 7, p. 270. July 26, 

 1899; from two hosts, 22. Aug. 14, 1899; from two hosts, 12. Aug. 28, 1899; from one host, 3. 



7. Rkynchohiithriuin tumlduhnn Lintim. Spiral valve. 2, ]iij. 829-832, pi. xi, figs, :i-ll. 5, ]i. 448. 7, 



p. 270. July 18, 1900; from one host, 6. 



8. JOniiirliiilxithrium hcterospinc Linton. S|)iral valve. 2, ])p. 8.39-840, pi. xii, figs. 3-5. 



9. JHu/itrlKjhothrium sp. Blastocyst, stomach. 4, p. 798, ]il. l.xiv, fig. 2. 



10. Tetrarhynchus sp. Cysts, stomach-wall. 4, p. 809, pi. lxvi, figs. 6, 7. 



11. Si/nholhrliimJilirolIi-lAnton. Cysts, stomach-wall. 4, pp. 815, 819, 820, jil. i,.\viii, fig. 9. 



Galeocerdo tigrinus {Gnhocerdfj niai-uhihis:), Tiger Siiiirk. 



FOOD. 



The stomach may contain a great variety of objects { 7, pp. 270-271), but fish, univalve niollusks, 

 and squid probably constitute the jirincipal food. The single specimen examined in 1899 had been 

 kept in confinement for two or three weeks and had nothing in the alimentary canal except two 

 opercula of the winkle (Symtypua canaliciilatiis), feathers of a flicker, and .some green seaweed in the 

 intestine. In the specimens examined in 1887 fragments of menhaden, bonito, and opercula of the 

 winkle were noted. 



NEM.\TOI)ES. 



1. Asmris breiiciijiltalii sp now; stomach. [PI. ni, figs. 19-22.] 



Four sjiecimens collectetl August 3, 1889, and a single specimen belonging to the National 

 Museum collection are of nearly uniform diameter for the greater part of their length, but are 

 attenuate anteriorly, particularly so for about 5 mm. at the anterior end; greatest diameter near 

 posterior end, which is recurved. Longest female 102 mm. in length and 1 mm. in diameter; body 

 marked with regular annulations about 0.008 mm. in length; (esophagus linear; spicules of male long 

 and slender; about 8 postanal and 30 or more preanal papilUe <:in each side; jaws very short and pro- 

 vided with papilla?. Dimensions of a male in millimeters: Length, 70; diameter of head, 0.17; length 

 of head, 0.08; diameter of botly one mm. back of head 0.56, one mm. from posterior end 0.75, at anal 

 aperture 0.37, maximum diameter 1.25; distance of anal aperture from posterior eml, 0.51. 



