142 Dr. G. C. Cramptoii on the Primilive 



and provisionally, at least, i have accepted his verdict 

 ill the matter. 



The cerci, labelled " c " in all figures, are fairly well 

 developed in Madolciines ; but the segments of the cerci 

 are not as distinct as in Terfiiojjsis (which is another feature 

 in which Termoims is more primitive than Maslotertnes). 

 There are traces of at least live segments in the cerci of 

 Mastolermes, and in all probability several more have 

 fused to form certain of the larger segments. 



The paraprocts, " pa," or lateral plates of the eleventh 

 segment, which bear the cerci, are quite well developed 

 in Mastolermes, as is also the case with the tenth tergite 

 " 10*," The posterior margin of the tenth tergite of the 

 winged male (fig. 2, " lOt ") is " indented " (or slightly 

 emarginate) mesally, while the posterior margin of the 

 tenth tergite of the winged female (fig. 1, " lOt ") is entire, 

 and is soiiiewhat " thinner," being more decurved posteriorly 

 than is the case in the winged male. 



In previous papers, I have appUed the term " epiproct " 

 to the tenth or to the eleventh abdominal tergites indis- 

 criminately, and I have also employed this term as practi- 

 cally synonymous with the designation " pygidium." In 

 the interest of exact usage, however, I would now suggest 

 that the term " epiproct " be restricted to the eleventh 

 abdominal tergite (which is distinguishable in but few 

 insects), while some form of the designation " pygidium " 

 should be employed for the apparent terminal tergite in 

 other cases. 



The term " pygidium " is frequently ajiplied to the 

 apparent terminal tergite in higher insects, regardless of 

 whether one is deahng with the actual sixth, seventh, 

 eighth, niiith, or tenth tergite, the actual terminal tergites 

 in such cases being usually withdrawn or " telescoped " 

 beneath the apparent termijud tergite wliich conceals them, 

 so that what appears to be the terminal tergite or " py- 

 gidium," is not actually the terminal one imder these con- 

 ditions. It would be much more exact when this is the 

 case, to prefix to the term pygidium, the Greek designations 

 hexa-, hepta-, octo-, ennea-, or deca-, to indicate that the 

 apparent last tergite is actuaUy formed by the tergite of 

 the sixth, seventh, eighth, ninth, or tenth segment, as the 

 case may be. Thus, the so-called " pygidium " of certain 

 Coleoptera is in reahty formed by the tergite of the sixth 

 abdominal segment (the termiiuil ones being usually with- 



