1919 J Cort: A New Distome from Bana aurora 297 



geana calif or niensis has a short esophagus and intestinal caeca 

 extending at least four-fifths of the distance from the anterior to 

 the posterior end, but not reaching into the posterior extremity 

 of the body. The pattern of the excretory system has never been 

 worked out for any species of the genus Brack ycocli urn. Looss 

 (1902, p. 815) describes the excretory bladder of Brack ycot Hum 

 salamandrae as club-shaped with the bifurcation reduced to mere 

 pockets at the anterior end, which differs from the condition of the 

 bladder in Marycaua calif orniensis, in which the reduction of the 

 bifurcation has been complete. The testes and cirrus sac are also 

 larger in Marycana calif orniensis than in the species of Brachycoelium. 

 It was for the reasons givi n above that I established the new genus 

 Ma/rgeana for my new distome and included it in the subfamily 

 Brachycoeliinae as amended by Odhner (1910, pp. 89, 90). This 

 subfamily as amended by Odhner contained only the genus Brack y- 

 coelium and therefore its diagnosis coincided with the diagnosis of 

 this genus. The inclusion of Margecma in the subfamily Brachycoe- 

 liinae requires its revision only in the characters of the digestive 

 system and the excretory bladder. Johnston (1912, p. 336) places the 

 genus Mesocoelium Odhner in the subfamily Brachycoeliinae. "While 

 the resemblances between these two groups are so great that they 

 indicate close relationship, the position of the ovary behind the testes, 

 and the difference in the position of the genital pore in Mesocoelium 

 lead me to doubt the propriety of placing this genus in the subfamily 

 Brachycoeliinae. 



There has been considerable uncertainty in regard to the systematic 

 position of the subfamily Brachycoeliinae. Odhner (1910, pp. 89, 90) 

 after his revision of this subfamily, placed it in his new family 

 Dierocoeliidae, considering it to be closely related to the subfamily 

 Dicrocoeliinae Looss. Differences in habitat and in structure of the 

 members of Dicrocoeliinae and of Brachycoeliinae suggest that this 

 grouping is unnatural. Ward (1918, p. 400) separates the subfamily 

 Brachycoeliinae from the family Dierocoeliidae. In my opinion the 

 subfamily Brachycoeliinae should be placed in the family Plagi- 

 orchiidae Luhe, syn. Lepodermatidae Odhner. The departure of the 

 excretory bladder of the subfamily Brachycoeliinae from the typical 

 V-shaped condition of the family Plagiorchiidae was shown above to 

 be a secondary modification. In all other features this subfamily falls 

 within the diagnosis of the family Plagiochiidae as given by Odhner 

 (1910, pp. 22, 23) and by Ward (191S, p. 402). 



