1898.] NATURAL SCIENCES OF PHILADELPHIA. 69 



longer than the penis and epiphallus taken together. The sperma- 

 theea duct bears no diverticulum. The dart sack is degenerate, 

 reduced to a small wide bud, one mucus gland arising at its right 

 side, descending, club shaped, the other at left side, ascending and 

 slightly sacculated ; both entirely free, not bound to the vagina. The 

 right eye-retractor passes to the left of the genital system, not between 

 its branches. 



The last characters may be expected to occur in E. facta and 

 rufieincta. It is a very unusual feature. The subobsolete condition 

 of the dart sack is unlike any allied species. The measurements 

 are: length of penis+epiphallus 9 mm.; of flagellum 10; of sper- 

 matheca duct 15 mm. 



The other forms examined have the flagellum very long, dart sack 

 well developed, one of the mucus glands descending, spread upon 

 the base of vagina, the other upon the dart sack, both bound down. 

 Diverticulum developed and long except in Stearnsiana. In all, the 

 spermatheca arises high, near the distal end of the vagina. The 

 dimensions of the parts are as follows : 



Pandoras. Veitchii. Areolata. Stearnsiana. 

 Length of penis+epiphallus 15 35 28 22 28 mm. 



Length of flagellum 21 67 50 26 27 mm. 



Length of spermatheca duct 17j 54 49 43 35 mm. 



Length of diverticulum 13 43 25 1mm. 



Thrown into the form of an analytical key, the genital characters 

 give these results: 

 a. Right eye retractor passing between $ and 9 branches of geni- 

 talia ; diverticulum presents one mucus gland spread upon and 

 firmly bound to vagina below dart sack. 

 b. Flagellum and spermatheca duct of about equal length, 



areolata. 

 bb. Flagellum longer than spermatheca duct ; diverticulum f 

 to I length of spermatheca duct, much longer than the 

 other branch. 



c. Penis-j-epiphallus J length of flagellum . . . Pandora. 



cc. Penis+epiphallus about i length of flagellum . Veitchii. 



bbb. Flagellum shorter than spermatheca duct ; diverticulum 



very short or wanting Stearnsiana. 



aa. Right eye retractor not passing between branches of genitalia ; 

 mucus glands free; no diverticulum ; flagellum about the same 

 length as penis+epij)hallus. 

 b. Dart sack degenerate, very small Guadalupia'na. 



