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PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 88 



One (U.S.N.M. No. 8203), collected September 22, 1913, from 

 crevalle; length 8 mm., breadth 0.6 mm., in formalin. Measurements 

 in balsam : Length, 7 mm. ; breadth, 0.46 mm. ; diameter oral circle of 

 spines, 0.22 mm.; oral sucker, length 0.11 mm., breadth 0.15 mm.; 

 pharynx (indistinct), length 0.15 mm., breadth 0.12 mm.; ventral 

 sucker, length 0.21 mm., breadth 0.24 mm. ; ova, 0.051 by 0.036 mm. ; 

 length of oral spines about 0.07 mm., of neck spines 0.015 to 0.03 mm. 

 This distome agrees rather closely with the distomes from S. lalandi. 

 The number of oral spines could not be determined exactly, but there 

 are at least 44 in the two circles. The neck is contracted, breadth 

 behind circle of spines, 0.14 mm., then expanding to a breadth of 

 0.45 mm. ; length of neck, that is, from anterior end to ventral sucker, 

 0.6 mm. Prepharynx longer than pharynx; cirrus pouch and sem- 

 inal vesicle long, extending 1.5 mm. back of ventral sucker ; distance 

 of ovary from first testis 0.5 mm., from first to second testis 0.15 mm., 

 from second testis to posterior end 0.5 mm.; uterus median, from 

 ovary to genital pore ; vitellaria dense, from posterior end to a point 

 1.4 mm. back of ventral sucker. 



Table 15. — Measurements of three specimens of Stephanostomum filiforme 



in balsam 



Measurement 



Length 



Maximum breadth. 



Oral sucker, length 



Oral sucker, breadth 



Pharynx, length 



Pharynx, breadth 



Ventral sucker, length 



Ventral sucker, breadth 



Length of prepharynx 



Anterior end to ventral sucker 



Ovary to first testis... 



Ova 



Mm. 



7.6S 

 .28 

 .14 

 .17 

 .14 

 .09 

 .25 

 .19 

 .77 



1.12 



.45 



0.06 by .04 



One and a fragment (U.S.N.M. No. 8204), collected October 13, 

 1911, from the cocinero ; 15 fishes examined : Length, 9 mm. ; breadth, 

 1 mm., in formalin. Measurements in balsam: Length, 7.14 mm.; 

 breadth, 0.35 mm. ; oral sucker, length, 0.13 mm., breadth, 0.15 mm. ; 

 pharynx, length, 0.18 mm., breadth, 0.19 mm. ; ventral sucker, length, 

 0.28 mm., breadth, 0.28 mm. (lateral view) ; length of oral spines 

 about 0.06 mm., of neck spines about 0.03 mm.; ovary, length, 0.21 

 mm., breadth, 0.14 mm.; first testis, length, 0.63 mm., breadth, 0.25 

 mm. ; second testis, length, 0.48 mm., breadth, 0.21 mm. ; distance from 

 ovary to first testis, 0.28 mm., from first to second testis, 0.14 mm., 

 from second testis to posterior end, 0.35 mm.; ova, 0.06 by 0.04 mm. 



