TREMATODES FROM FISHES — LINTON 95 



In balsam, length, 0.54 mm.; breadth, 0.12 mm.; diameter of oral 

 sucker, 0.03 mm., of pharynx, 0.02 mm., of ventral sucker, 0.03 mm. ; 

 length of prepharynx, 0.03 mm., of esophagus, 0.04 mm. Kudiments 

 of genitalia agree in relative positions with this species. 



LEPIDAPEDON RACHION (Cobbold) 



Plate 5, Figure 46 



Lepidapedon rachion (Cobbold), Stakfoed, Zool. Anz., vol. 27, p. 487, 1904. — 

 Mantbr, Illinois Biol. Mon., vol. 10, No. 2, pp. 84, 85, figs. 45, 46. 



Lepodora rachiaea (Cobbold), Odhner, Die Trematoden des arktischen Gebietes, 

 Fauna Arctica, vol. 4, p. 332, pi. 2, figs. 12-15, 1905. 



Distomes referred to this species were found in the sea bass, cod, 

 haddock, and silversides. Differences in details of structure, which 

 are many, may generally be accounted for by differing states of con- 

 traction, and differences in age. In general the outline is long oval, 

 usually tapering more anteriorly than posteriorly, the neck and 

 anterior part of the body bearing short, scalelike spines, which are 

 evanescent; ventral sucker smaller than oral; pharynx relatively 

 large ; prepharynx as long, or longer, than pharynx ; esophagus very 

 short, often indistinguishable ; genital pore in front of ventral sucker, 

 on median line; cirrus-pouch in front of, and dorsal to ventral 

 sucker; the seminal vesicle, often large, and extending back of the 

 ventral sucker; testes two, one following the other; ovary in front 

 of first testis and near it; testes and ovary relatively small and 

 rounded; vitellaria diffuse, extending from the posterior end to the 

 level of the ventral sucker. Other details, including measurements, 

 given under the several hosts. 



Hosts. — Black sea bass {Centropristes striatus), common codfish 

 {Gadus TTiorrhua), haddock {MelanogramTnus aegelflnus) ., silversides 

 {Menidia notata) . 



Record of coUectioois. — One, from black sea bass, collected July 9, 

 1904. Measurements, life : Length, 3.23 mm. ; breadth, anterior 0.37, 

 at level of ventral sucker, 0.67 mm., near posterior end, 0.22 mm.; 

 diameter of oral sucker, 0.35 mm., of pharynx, 0.26 mm., of ventral 

 sucker, 0.24 mm.; ova, 0.05 by 0.04 mm. Measurements in balsam: 

 Length, 2.1 mm.; maximum breadth, 0.4 mm.; diameter of oral 

 sucker, 0.21 mm.; pharynx, length, 0.14 mm., breadth, 0.15 mm.; 

 diameter of ventral sucker, 0.15 mm. ; length of prepharynx, 0.21 mm,, 

 of esophagus, 0.03 mm. ; ova, 0.054 by 0.030 mm. In this distome from 

 the sea bass the vitellaria extended forward about to the level of the 

 anterior border of the ventral sucker and the ovary was a little more 

 to the left than to the right of the median line. 



