58 PROCEEDINGS OF THE NATIONAL MUSEUM vol.88 



pp. 444, 464, 1901. One, collected August 17, 1909, in cyst from file- 

 fish. Specimens collected July 13, 1911, in cysts on intestine of file- 

 fish; length, 1.12 mm., breadth, 0.8 mm. Large numbers of spherical 

 cysts, collected August 21, 1915, from filefish, widely distributed in 

 the muscles from tail to head, and between the vertebral spines, both 

 haemal and dorsal ; also in the peritoneal cavity, on the viscera and on 

 the ventricle. In the flesh the spherical cysts, from 0.06 to 2 mm. 

 in diameter, are enclosed in larger cysts 4.5 by 2.5 nam. Cysts on the 

 ventrical and viscera are globular, without any of the white, granular, 

 or cheesy material w^hich is associated with the cysts in the flesh. 



Many spherical cysts, collected September 6, 1927, from filefish 

 in peritoneal cavity, on auricles and on mucous membrane of 

 pharynx; a double circle of hooks around the mouth, about 32 in each 

 circle. 



Recorded from silversides: Bull. U. S. Fish Comm. for 1899, p. 

 444, 1901. Many globular cysts on viscera of silversides, collected by 

 Dr. Irving A. Field on August 25, 1904. Few small cysts, collected 

 August 30, 1910, from silversides; transparent, amber colored, and 

 containing opaque distomes; cysts 0.8 mm. to 1 mm. in diameter; 24 

 fishes examined. 



One, collected July 6, 1901, from toadfish; small, yellow, globular 

 cyst, containing a distome with double circle of spines around mouth ; 

 about 24 spines in each circle. Few cysts on mesentery of toadfish, 

 collected August 22, 1903. Four cysts on mesentery of toadfish col- 

 lected August 25, 1903. Two cysts in stomach wall of toadfish, col- 

 lected August 4, 1908. 



A distome (U.S.N.M. No. 8210), collected from a sunfish, July 19, 

 1926, is here recorded. The specimen is not in good condition, having 

 lost all the oral, and the greater part of the cuticular, spines. The 

 neck is relatively longer and slenderer than in S. dentatum; also 

 there is a seminal receptacle, which has not been observed in the dis- 

 tomes from the flounder. Measurements in balsam: Length, 1.82 

 mm.; breadth, 0.4 mm.; oral sucker, length, 0.12 mm., breadth, 0.14 

 mm.; pharynx, length, 0.12 mm., breadth, 0.06 mm.; ventral sucker, 

 length, 0.18 mm., breadth, 0.25 mm.; ova, 0.054 by 0.027 mm., 0.06 by 

 0.036 mm. 



Another small distome was noted that had spines around the mouth, 

 but unfortunately it was lost before measurements had been made. 



STEPHANOSTOMUM species 



Plate 4, Figures 29-31 



Host. — Great amberfish {SeHola lalandi). 



Three of the distomes (U.S.N.M. No. 8211), collected from this 

 host, September 20, 1910, differ from the others obtained on this 



