A TAXONOMIC STUDY ON PYKOSOMA — METCALF AND HOPKINS. 259 



and probably with its subspecies paradoxum, 1 as well as with members 

 of the group "intermedium"; but a better expression of the condi- 

 tions seems to be to sav that any of these forms mentioned mav be 



flattened, that is, may take on the dipleurosoma condition. In the 

 chart, the small circles containing the letter "h" indicate forms in 

 our collection interpreted as hybrids. 



i United States National Museum, Cat. Nos. 6469 (type) and 6420. 



