262 The Molluscan Family Planorhidae 



PLATE 13 



Tropicorbis 



1-3. Tropicorbis obstructus (Morelet). From New Orleans, La.; collected by Dr. E. C. 

 Faust. 



1. Genitalia dissected and organs separated. 



2. Cross section of ovotestis in non-gravid stage. 



3. Cross section of ovotestis in gravid stage with ova in diverticula. Line at right 



indicates 0.5 mm. in length. 



4-10. Tropicorbis riisci (Dunker). From Lares, Puerto Rico; from Dr. W. A. Hoffman. 

 4,5. Cross sections of prostate diverticula showing bending at end. Also presence 

 of prostate duct distinct from sperm duct. 



6. Penial complex, external view\ 



7. Albumen gland from below showing duct (DA). 



8. Vas deferens showing branching to form sperm duct and prostate duct (greatly 



enlarged) . 



9. Portion of genitalia dissected and organs separated. Organs as in fig. 1. 



10. Head of animal showing pseudobranch and imeumostome as well as ridge over 

 rectum. 



Line near figure indicates 1 mm. in length. Line at left of 

 figs. 4 and 5 is for both figures. 



