PARASITES OF FISHES OF THE WOODS HOLE REGION. 475 



•1. Dililonmm ocreatuw Molin. Stoniafh. 7, pp. 2.So, 2SS, |)1. xxxv, fig,«. Ki-24. See O, pp. 514-515, 



pi. XLII, fig. l.S. 



Microgadus tomcod, Tuhicad. 



FOOD. 



Anneliils, shrimp, amphipods, and other small crustaceans fi)nnil in tlie alimentary canals. 



NEMATODKK. 



1. AKcaria sji. [PI. i\, tigs. 97-99.] Immature. Intestine. Found in .Iidy ISSfi, Aug. 1SS7, and 



1899; few. In intestine near pyloric Cfeca; length, 25 to 35 nnn; pmliably the youngot Anniris 

 clavata. 



CESTODES. 



2. Larv<(l restodes {SroJex poJymorplms'Duia.rdin). Free in intestine. Aug. 2, 1900. See 4, p. 789, etc. 



3. R}iiiiichohf)lhrin)ii inijHirlspme Linton. Encysted on viscera. 4, ])p. 799-,S()l. pi. i.xiv, tigs. 9-12. 



4. RliiiiiiliiiholJii-itini sp. F.ncysted, snlinuicosa of intestine and iieritonenm. -I, |i. 7vi4, pi. i,\iii, lig. 2. 



TREMATODES. 



5. DkUiiiiiuH uppoidicahituiii Kudolphi. Intestine. Aug. 2, 1900. See 7, p. 289, pi. xxxvi, iigs. 25,26. 



6. Distoinum simple.v Rudolphi. Intestine. [PI. xxx, tigs. 331, 332.] 6, pp. 525-526, pi. xi.vii, figs. (3, 7. 



Aug. 13, 1900; 3. 

 These distonies when first seen were yellowish white, nearly transparent, the surface i-orrugated 

 l)y fine transverse lines. They then resenililed very closely the small distonies (No. 19 ini<ler P. dentatus 

 [fig. 330] ) from the flounder collected August 17, 1899. When a specimen, which was quite short and 

 corrugated and kept imder slight pressure, was hel<l over the flame of an alcohol lamp and warmed 

 sufliciently to stiffen it, the body relaxed and became much elongateil. After seeing the diverse shapes 

 which distonies of the same species assume under different conditions of develojiment and contraction 

 one realizes the inadvisability of bestowing specific names on new forms in the absence of a good 

 nundaer of specimens. Tliese specimens varied from 1.22 mm. to 2.47 nun. in length. A few- 

 dimensions of a specimen in glycerine given in millimeters are: Length, 2.40; breadtli, 0.44; oral 

 sucker, length 0.19, lireadth 0.17; diameter of pharynx, 0.09; acetabulum, length 0.25, breadth 0.29; 

 ova, 0.08 and 0.04 in the two principal diameters. 



Gadus callarias (Gadus mnrrlinii) , Cod. 



ACAXTHOCEPnALA. 



1. Erhindrhyndius dcus Rudolphi. 



Eleven lots in the National lluseum collection from Woods Hole, collected in November and 

 December, 1887; two in Jannary, 1888, by Mr. Vinal N. Edwards; one collected August 22, 1883, 

 and one from Eastport, Me. (Palmer, collector). Three of these lots contain very numerous specimens; 

 the others range from 1 to 54. These specimens from the cod, while showing considerable variety in 

 shape and size, agree closely in the maximum and minimum dimensions. The females in nearly every 

 lot measure from 28 mm. to 30 mm. in length, and the males from 6 nnn. to 8 mm. 



NEMATODES. 



2. Ascnrls claraln Rudolphi. Stomach. 



Eleven lot.s of nematodes from this host, seven collected at Woods Hole, by Vinal N. Edwards, 

 in November, December, 1887, and January, 1S88; one lot collected by Mr. Thomas Lee on the 

 steamer AUmtrosH, August 22, 1883; one from a salt cod, collected liy Mr. A. II. ('lark; one from 

 Long Island, collected by Mr. S. E. Meek, ami one from Ca.sco Bay, while presenting many individual 

 variations, appear to belong to this species. The specimens in these lot.s var}- from mm. t(.) 02 mm. 

 in length. The smaller are relatively more slender llian the larger ones, whicli wen' considerably 

 thickened ]>osteriorly. 



Dimensions of two specimens, in millimeters: 1-ength, male 30, feinale 48; diameter of head, 

 male 0.28, female 0.30; diameter 2 mm. back of head, male 0.80, female 0.70; diameter middle, male 

 0.85, female 1.10; diameter 2 mm. from posterior end, male 0.80, female 1 ; diameter at anal aperture, 

 male 0.25, female 0.35; distance of anal aperture from ]iosterior end, male 0.15, female 0.28. 



