PLATE XXIII. 



[Proc. Wash. Acad. Sci., Vol. II, PI. XIX.] 



(All figures drawn bj aid of a camera lucida except ^a, ii, 12, and 13.) 



Fig. 1. Menipeaerecta s^.nov. Frontal view, showing bifurcation of an inter- 

 node and main points of structure; spine (5^.), operculum i^op.^, 

 frontal avicularia (/". a.), oecia («.), and mode of articulation {ari.). 



2. Dorsal view of the same, showing the radical fibers {r, f.) and the 

 place of their attachment upon the zoecia. 



3. Scrupocellaria scabra Van Beneden, frontal view. 



4. Dorsal view of the same, showing absence of vibracula. 



[336] (244) 



