190 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.48. 



Superfamily BRANCHIOBDELLOIDEA Hall, 1914. 



Superfamily diagnosis. — Annulata: Modified oligochaetes with the 

 characteristics given in the foregoing part of the paper. 

 Type and only family. — Branchiobdellidae. 



Family BRANCHIOBDELLIDAE. 



Family diagnosis. — Branchiobdelloidea: With the characters of the 

 superfamily. 



Type genus. — BrancMobdella Odier, 1823. 



The following key to the genera of Branchiobdellidae is based in 

 part on Pierantoni's (1912) paper and partly on Ellis's (1912) paper: 



1. Trunk region provided with dorsal or ventral appendages 2 



Trunk region smooth, not provided with such appendages 4 



2. Trunk region bearing appendages on dorsal side 3 



Trunk region bearing appendages on ventral side Cirrodrilus. 



3. Head not provided with tentaculiform appendages Pterodrilus. 



Head provided with tentaculiform appendages Ceratodrilus. 



4. With 1 pair of testes BrancMobdella. 



With 2 pair of testes 5 



5. Prostomium plurilobate, with or without digitiform appendages. . .Stephanodrilus. 

 Prostomium entire or divided into a dorsal and ventral lobe 6 



6. Spermatheca bifid, dental plates colorless, penis eversible, pair of large clear glands 



in each of 9 post-cephalic segments Bdellodrilus. 



Spermatheca not bifid, dental plates colored, penis not eversible, no large clear 

 glands in the 9 post-cephalic segments Cambarincola. 



Key to the North American species of Branchiobdellidae. 



BrancMobdella Odier, 1823. 



Prostomium entire, dental plates dissimilar, the dorsal with 5 and ventral with 4 



teeth B. americana. 



Prostomium bilobed, dental plates with 2 lateral and 2 median teeth. ,B. tetrodonta. 



Bdellodrilus Moore, 1895. 



1. Dental plates dissimilar Bd. illuminatus. 



Dental plates similar 2 



2. Prostomium entire Bd. instabilis. 



Prostomium bilobed Bd. pulcherrimus. 



Pterodrilus Moore, 1895. 



Dorsal appendages on segments 3, 4, 5, and 8 Pt. alcicornus. 



Dorsal appendages on segments 2 to 8, inclusive Pt. distichus. 



Cambarincola Ellis, 1912. 



Head as wide as or wider than greatest body width, campanulate; 1 lip, slightly 

 crenate; dorsal plate with 7 teeth, ventral with 10 C. philadelphica. 



Head not as wide as greatest body width, tapering anteriorly; 2 lips; dorsal plate with 

 5 teeth, ventral with 4 C. macrodonta. 



