TEEMATODES FROM FISHES — ^LINTON 97 



acters that it is not advisable to recognize tlieir differences as of 

 specific value. 



Body more or less linear, although the proportions vary greatly 

 with different stages of contraction, neck more or less tapering. 

 Neck and anterior portion of body covered with short, blunt spines, 

 becoming sj^arse posteriorly, more or less evanescent; oral and ven- 

 tral suckers not differing much in size; pharynx much smaller than 

 oral sucker, usually a little longer than broad; prepharynx and 

 esophagus both present, their relative lengths variable, depending on 

 contraction conditions; intestines extend nearly to posterior end of 

 body, often hidden by the vitellaria ; genital pore in front of ventral 

 sucker, median; cirrus pouch lacking; ejaculatory duct and seminal 

 vesicle dorsal to the ventral sucker, usually to the right of the median 

 line, the seminal vesicle extending back of the ventral sucker as far 

 as the ovary, the anterior border of which it often overlaps. The 

 two testes are situated about midway between the ventral sucker and 

 tlie posterior end, in many cases more or less lobed; ovary in front 

 of first testis to the right of the median line, not lobed ; shell gland 

 and yolk reservoir between the ovary and first testis; seminal recep- 

 tacle in front, and dorsal to the ovary on the right side of the seminal 

 vesicle; vitellaria diffuse, from posterior end to, or nearly to, the 

 level of the posterior margin of the ventral sucker ; ova few, in front 

 of testes, 0.09 or 0.1 mm. in longer, by 0.07 mm. or more in shorter 

 diameter. 



Further details given in record of collections. 



Hosts. — Mademoiselle {Bairdiella chrysura)^ common killifish 

 {Fundulus heteroclitus) ^ spot {Leiostomus xanthurus), kingfish 

 {Mentifylrrtms saxatilis)., white perch {Morone americana) , winter 

 flounder {Pseudopleuronectes americanus) ., tautog {Tautoga onitis). 



Record of collections. — Three (U.S.N.M. No. 8288), from made- 

 moiselle, collected September 10, 1928; 4 fishes, 62 to 68 mm. in length, 

 examined, seined at Wareham. Measurements, balsam : Length, 2.87 

 mm.; breadth, 0.59 mm.; diameter of oral sucker, 0.21 mm., of 

 pharynx, 0.11 mm., of ventral sucker, 0.21 mm.; ova, 0.096 by 0.069 

 mm. These distomes resemble those from M. saxatilis, collected on 

 the same date and from the same locality. Spines evanescent; pre- 

 pharynx a little longer than pharynx, esophagus about same length 

 as pharynx. 



From common killifish: Seven (U.S.N.M. No. 8289), collected 

 January 10, 1917, from one fish, eight fishes examined. 



From spot: Collected by Vinal N. Edwards on 16 dates in the 

 months of September and October in the years 1912, 1913, and 1914. 

 His record shows a total of 40 distomes from 231 fishes. The largest 



155599—40 7 



