﻿NORTH AMERICAN NOTOSTRACA — LINDER 



63 



As I have said, the presence of such spines will not do as a specific 

 character. 



The total numbers of body-rini;s in table 7 might give the impres- 

 sion that we have, at last, found a distinguishing character for A. 

 aequalis in its relatively low number. This would tally well with 

 Packard's statement that this species has a short body in relation 

 to the length of the carapace and that comparatively few rings are 



L enffth of carapace > 



Average: ffl^io* OZJmm 

 ? ? IS.7JtO./^mm 



dumber of obdomina/ 

 tegbearing bod(/~rinffs 

 Average: <f<3' 17.26 1 0. t2 

 %% 19.19 t 0.06 



JiS ■»7 49 SI 53 SS 

 A/umber of pairs of fegs 

 on the abdamfn 

 Average: ^<^^7.2lt0.32 

 % % 50.S2tO.i7 



J9 4C W il il ■>2 iZ^'ili* 



Totat number of body -rings 

 {isfson excluded) 

 A veroge . rf'o" <.p. is ± 0. I2 

 (inotcmsidmii) ? % ^C. 99 +0.07 



Figure 31. — Variations in the length of the carapace, number of legs, number of abdominal 

 leg-bearing rings, and total number of rings in a population of 33 males and 98 females 

 of Apus longicaudatus LeConte, from near Aurora, VVyo. (U.S.N.M. No. 58766). Males 

 indicated by dashed lines, females by solid lines. Correlations of various kinds to be 

 considered in a later paper. 



exposed beyond the carapace. But a look at the para types of A. 

 lucasanus contradicts this conclusion. There is a male with the same 

 number as the type specimen of aequalis (38 +i), and others with a 

 little lower or higher number. The female has a number which is 

 only slightly higher than that of the types of A. aequalis. As I have 

 found (see table 8), the total number of rings in American forms of 

 Apus present a continuous series from 34 + i to 43 in the females and 



