4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 9I 



wardsia "-mesenteries are perfect and provided with pennons. The 

 pennons (fig. 2) are concentrated and more or less kidneyHke in cross- 

 sections, the muscle folds often much ramified. The outer lamellar 

 part of the perfect mesenteries is attached to the pennons on their 

 outside. The parietal muscles present on all 12 mesenteries are strong, 

 the supporting folds of the mesogloea are thin and rather much rami- 

 fied on the inside, coarse and few on the outside (fig. 3). The parietal 

 muscles are not expanded on the column. The ciliated tracts of the 

 filaments are well developed. Only the 8 " Edwardsia "-mesenteries 

 are provided with testes which are well developed. 



