164 THE SHORTER SCIENTIFIC PAPERS 



to the neuropodium and notopodium of the parapodia. 

 These two pieces, I am inclined to believe, represent the 

 episternum and epimeron of the thorax. Even among 

 many of the Chilopods, where there has apparently been 

 a secondary breaking up of the pleura into numerous 

 sclerites, there are still two principal areas demonstrable 

 in each pleurum. Snodgrass (1909) has called attention 

 to this characteristic. 



The anterior portion of the coxa, as noted in the ac- 

 companying drawings, I have termed the coxon. This is 

 the area which I earlier called the coxa genuina and which 

 has been mentioned by later writers as the eucoxa and the 

 coxa vera. While from certain standpoints it may be con- 

 sidered unfortunate that a priority principle does not 

 enter into anatomical nomenclature in the strict sense 

 that it exists in systematic work, a mononomial is here 

 certainly to be preferred to a binomial term, and the 

 word coxon, while open to objections from the classical 

 side as is also the hybrid "eucoxa," possesses the merit of 

 brevity as well as a relatedness to the terms meron and 

 coxa. 



Whether an attempt to reduce the confusion of ana- 

 tomical nomenclature in the insects by presenting new 

 terms for typical generalized structures is justified will 

 remain for future students of the anatomy of insects to 

 decide. 



The stylus attached to the meron represents, I am in- 

 clined to believe, a dorsal cirrus of the Polychaete para- 

 podium, although two other possibilities present them- 

 selves — the one that it is the modified distal area of the 

 notopodium with the terminal tip composed of setae 

 formed from the notopodial aciculum, while the other is 

 that it represents the development of a small setae and 

 is wholly of a secondary character, as Haase (1889^) has 

 suggested. The explanation on the basis of a modified 

 notopodial cirrus, which in the different segments has 

 evolved into the maxillary and labial palpi, the mesotho- 

 racic and metathoracic styli (Machilidae), the abdominal 

 styli of many Apterygotes and in all probability the tra- 

 cheal gills of the Ephemeridae, etc., as well as the cerci 



