ART. 13 TEEMATODE PAEASITES OF MAEINE MAMMALS PRICE 39 



posterior half of body. The uterus begins with irregular transverse 

 coils on the left side of ovary, then passes to the right around the 

 ovary and forms two transverse loops caudad of the acetabulum, the 

 loops extending into the extracecal fields; vagina nearly straight, 

 14:0fx long, opening close to the male aperture. Eggs 23 to 28ju, long 

 by 13 to 15/i, wide. 



Host. — Phoca hisplda. 



Location. — Intestine. 



Distribution. — Asia (Japan — Hanayashiki Zoological Garden, 

 Tokyo). 



Genus GALACTOSOMUM Looss, 1899 



Synonyms. — Mic7'olistruni Braun, 1901b, p. 5G3 ; G ercarioides Wit- 

 enberg, 1929, p. 138. 



Generic diagnosis. — Heterophyidae : Body elongated and spindle- 

 like in outline, or expanded anteriorly and more or less cylindrical 

 posteriorly. Prepharynx usually distinct, longer than esophagus; 

 intestinal ceca simple, extending to posterior end of body. Genital 

 aperture situated medially, about one-third of the body length from 

 the anterior end. Genital sinus complicated, containing a spiny, 

 spheroidal, more or less muscular body (gonotyl ?) imbedded in the 

 dorsal wall of the sinus. Seminal vesicle well developed, free in 

 parenchyma, the terminal portion of the vesicle being provided with 

 a muscular wall (expulsor). Testes ovoid, spherical or slightly 

 lobed, tandem or slightly oblique in position, and situated in the 

 posterior half of the body. Ovary spherical or ovoid in shape, situ- 

 ated slightly to the right of the median line and cephalad of the 

 seminal receptacle. Vitellaria extracecal or expanding medially in 

 the posttesticular space, and extending anteriorly as far as the an- 

 terior testis or beyond. Uterus with a descending and an ascending 

 limb, both passing between testes. 



Type species. — Galactosonium lacteum (Jiigerskiold, 1896) Looss, 

 1902. 



Remarks. — The genus Galactosomum was proposed by Looss 

 (1899) to contain Monostomum lacteum Jiigerskiold. Braun (1901b) 

 proposed the genus MieroUstrutn to contain three species, Distomutn 

 coclileariforme Kudolphi, 1819, D. cochlear Diesing, 1850, and M. 

 spinetum Braun, 1901b. Odhner (1910a) pointed out that the struc- 

 ture which Braun interpreted as an acetabulum in the species in- 

 cluded in the genus Microlistrum was the same structure as that 

 described by Jiigerskiold (1896) as the " stacheligen Korper " in 

 Galactosom/wm lacteum.. Other similarities were also noted between 

 the two genera. Pratt (1911) gave a redescription of M. cochleari- 

 forme and showed that the character of the genitalia was essentially 



