192] LIFE HISTORY OF GORDIUS AND PARAGORDIUS—MA Y 71 



Posterior end of male provided with two projecting lobes or prongs arising 

 a short distance behind the anus. A post-anal crescent is present and has 

 its tips directed toward the prongs. Posterior end of female entire. Larva 

 with elongated body and pointed posterior end. Only genus in family: 

 Gordius. 



The limits of the new family Chordodidae are the following: Gordiacea 

 with rough cuticula, presenting true areoles. Tubercles and bristles arising 

 from the non-fibrous cuticula. Ovaries enclosed by mesenchyme, conse- 

 quently double mesenteries present in the female. Posterior end of male 

 forked or provided with a dorso-ventral groove. Post-anal crescent absent. 

 Posterior end of female entire or provided with three lobes. Larva with 

 short body, rounded at posterior end and provided with postero-lateral 

 spines. Genera included in family: Chordodes, Paragordius, Parachordodes. 



The evidence presented in this paper shows clearly that the supposed 

 relationship to the Annelida does not exist. True coelom and segmentation 

 are absent. Other workers have already shown that there is in the develop- 

 ment of the Gordiacea no trace of the trochophore larva of the Annelida. 

 Almost the only thing in common for the two is the ventral position of the 

 nerve cord and its passage around the esophagus. 



The evidence for a possible relationship to the Nematoda is strength- 

 ened by the discovery of a moult in the development of the Gordiacea and 

 by the establishment of the absence of cilia or a true coelom in that group. 

 The absence of a complicated metamorphosis and the fact that the pro- 

 boscis is not exclusively a larval organ remove some of the objections to 

 such a relationship. 



