rayburn: chromosomes of nomotettix. 269 



Nomotettix is farther away from Paratettix than from 

 Acridium. For instance, there is a much less extreme range of 

 length shown in Paratettix than in Nomotettix. Compare the 

 ratios 9.82 to 27.75, the relative lengths of Nos. 1 and 6 of 

 Nomotettix, with 11.4 to 23.6 and 11.4 to 23.7 of Paratettix 

 cucculatus and texana, respectively, and also with 10.48 to 

 28.14 and 10 to 29.4 of Acridium granulatus and obscurus, re- 

 spectively. 



Likewise, the sex chromosome in Nomotettix is relatively 

 shorter than in the species of Paratettix. Here it ranks be- 

 tween the second and third autosomes in spermatogonia, hav- 

 ing the value of 13.34. In the spermatogonia of Paratettix it 

 ranks between the second and third autosomes, but has the 

 value of 13.9. In the first spermatocytes its rank is between 

 the fourth and fifth autosomes and has a value of 17.2 in Para- 

 tettix cucculatus and 17.8 in P. texana. In Acridium it ranks 

 either between the second and third autosome or below the 

 first autosome. Its length is very short, having the value of 

 either 11.95 or 8.7 in spermatogonia, or for first spermatocyte 

 13.45 (ranking between second and third, but low), 11 (rank- 

 ing with No. 1), 7.9 (ranking below No. 1), and 12.09 (rank- 

 ing between 2 and 3) . It will be seen that in so far as size of 

 the sex chromosome is concerned, Nomotettix is nearer to 

 Acridium than to Paratettix. 



As regards relations with the genus Tettigidea, Nomotettix 

 is about the same distance away as Acridium. In this genus 

 the two long chromosomes are relatively not so long, 22.3 and 

 24.6, and are more nearly equal in length, while in Nomotettix 

 they are very unequal in length, as in Acridium. The sex 

 chromosome in Tettigidea ranks fifth in the series, while in 

 Nomotettix, as already mentioned, it ranks third. 



CONCLUSIONS. 



1. Nomotettix agrees with all other genera of the family 

 Tettigidae in having in the male six pairs of autosomes and one 

 sex chromosome. 



2. It agrees with those genera of the family so far exam- 

 ined in that the pairs of autosomes readily arrange themselves 

 according to length into three groups — two shorts, two inter- 

 mediates, and two longs. 



3. In the relative lengths of the autosomes this species of 

 Nomotettix agrees more readly with species of Acridium than 



