110 PKOCEEDINGS OF THE NATIONAL MUSEUM vol.88 



ventral sucker, 1.09 mm.; cirrus pouch, length, 0.23 mm., breadth, 

 0.21. mm. 



Fourteen, immature, collected July 17, 1924, encysted in submucosa 

 of stomach, surrounded by black, granular pigment; some of them 

 rather active after liberation from cysts. Measurements, life, com- 

 pressed : Length, 8 mm., breadth, 1.40 mm. ; oral sucker, length, 0.67 

 mm., breadth, 0.53 mm. ; pharynx, contracting and expanding, length 

 and breadth at time of measuring, about 0.28 mm.; ventral sucker, 

 length, 0.95 mm., breadth, 0.92 mm. 



Two, immature, collected July 7, 1926, from cysts on viscera of host. 

 Seven, collected August 12, 1926, in dark-brown cysts in stomach wall. 

 Measurements in balsam: Length, 0.6 mm.; breadth, 1.61 mm.; oral 

 sucker, length, 0,53 mm,, breadth, 0.56 mm.; pharynx, length, 0.28 

 mm., breadth, 0.21 mm.; ventral sucker, length, 0,95 mm., breadth, 

 0,91 mm,; cirras pouch, length, 0,21 mm,, breadth, 0,14 mm. 



Ratio of suckers, average of six in balsam: Oral sucker, length, 

 0,503 mm., breadth, 0.588 mm.; ventral sucker, length, 0.875 mm., 

 breadth, 0.871 mm. 



From rudderfish: One, immature, collected August 22, 1910; re- 

 corded here provisionally. 



Note made at time of collecting : Length, 5 mm. ; breadth, 1 mm. ; 

 thickish, white, smooth, nearly linear, bluntly tapering at each end; 

 dark intestine showing through body wall; black contents of excre- 

 tory vessel pressed out at excretory pore when cover glass was placed 

 on specimen; genitalia not developed. Measurements in balsam: 

 Length, 4.34 mm., breadth, 0.70 mm. ; oral sucker, length, 0.30 mm., 

 breadth, 0.38 mm.; pharynx, length, 0.25 mm., breadth, 0.22 mm.; 

 ventral sucker, length, 0.46 mm., breadth, 0.53 mm. The intestines 

 extend to the posterior end ; no trace of genitalia. 



Family HEMIURIDAE Looss, 1907 



Subfamily Sclerodistominae Odhner, 1927 



Genus HIRUDINELLA Blainville, 1824 



HIRUDINELLA FUSCA (Bosc) 

 Plate 12, Figures 134r-144 ; Plate 13, FiGtruES 145-1.57 



Distomum clavatum Rudolphi, Linton, Proc, U. S. Nat. Mus., vol. 20, pp. 539, 

 540, pi, 53, figs. 8-11 (from Xiphias gladius), 1898; Bull. U. S. Fish Comm. 

 for 1899, p. 445 (from Thtinnus thynnus), p. 448 (from Xiphias gladius), 

 1901. 



Distomum laffenifotine Linton, Proc. U. S. Nat. Mus., vol. 20, pp. 524, 525, pi. 47, 

 figs, 1, 2, 1898 ; Bull. U. S. Fish Comm. for 1899, from Reniora rcmora, prob- 

 ably belongs here. 



Distomum fuscum Poirier (Bosc), Mijhlschlag, Zool. Jahrb., vol. 37, pp. 217- 

 232, pi. 9, figs. 4-7, 8 figs., 1914. 



