34 PROCEEDINGS OF THE NATIONAL MUSEUM vol.88 



posterior end to within a short distance of the anterior end. The 

 dark brown ova are usually massed in the midregions of the body 

 obscuring the other genitalia. The ova have thickish, noncollapsed 

 shells, bluntly rounded at one end, pointed at the other. 



Measurements, formalin specimens in glycerin: Length, 2.8 mm., 

 breadth, 0.35 mm. ; diameter circle of tentacles, 0.17 mm. ; diameter of 

 neck behind tentacles, 0.14 mm.; anterior sucker, length, 0.11 mm., 

 breadth, 0.1 mm.; ventral sucker, length, 0.072 mm., breadth, 0.075 

 mm. ; ova, 0.024 by 0.013 mm., 0.024 by 0.018 mm. 



In a specimen 2.22 mm. long the ventral sucker was 1,22 mm. from 

 the anterior end. 



The above description is based on material from the northern 

 barracuda {Sphyraena horealis). 



Hosts. — Northern barracuda {Sphyraena horealis), American 

 smelt {Osmerus inordax).^ Spanish mackerel {Scotnberomorus mac- 

 ulatus), mackerel scad {Decaptenis macarellus) , kingfish {Menti- 

 cirrhus saxatilis), clear ray {Raja diaphanes)^ barndoor skate {R. 

 laevis). 



Record of collections. — ^All collections made by Vinal N. Edwards 

 in the months of April, September, October, and November, on 13 

 dates, in 5 different years, from 1908 to 1913. (U.S.N.M. No. 8180.) 



From barracuda: One hundred, more or less, collected April 24, 

 1908. Many, collected September 27, 1910; 10 fishes examined. 

 Eight, collected September 11, 1911, from one fish. Four hundred 

 and sixty, more or less, collected October 10, 1911. Twenty-five, col- 

 lected October 11, 1911. Two thousand two hundred and fifty, esti- 

 mated, collected October 23, 1911; 40 fishes examined. Twenty-one, 

 collected October 22, 1912 ; 100 fishes examined. Many, collected Octo- 

 ber 29, 1912; 150 fishes examined. Many, collected November 18, 

 1912 ; 18 fishes examined. One, collected September 18, 1913 ; 4 fishes 

 examined. 



Two hundred and twenty-three, collected October 25, 1913 ; length, 

 4.27 mm., more or less, in formalin; 120 fishes examined. One hun- 

 dred and sixteen, more or less, collected October 29, 1913; 100 fishes 

 examined. 



From smelt : Five, collected by Vinal N. Edwards, October 23, 1911, 

 8 fishes examined. Tliese specimens, in formalin, were in poor con- 

 dition, being more or less macerated. Length in formalin, 2.24 mm., 

 breadth, 0.22 mm. In a balsam specimen the diameter of the ventral 

 sucker is 0.06 mm. ; anterior sucker, length, 0.12 mm., breadth, 0.09 mm. 

 Ova, pointed at one end, 0.022 by 0.014 mm., in formalin. 



From Spanish mackerel : One, collected August 10, 1904, specimen 

 imperfect. A reexamination of Gasterostoma collected from the 

 Spanish mackerel at Beaufort, N. C, and at Woods Hole, Mass., 



