NO. 3600 GLOIOPOTES — CRESSET 13 



row consists of 3 spines but occasional variation was noted (some rows 

 have 1, 2, or 4 spines). In the large sample of 50 adult females of 

 G. huttoni from a single population, 12 (24 percent) varied from the 

 usual 3-3 arrangement. In this sample there was a higher incidence 

 (33 percent) of variation in the lower thu'd length range (shortest) ; a 

 somewhat lower incidence (25 percent) in the middle third group; 

 and lowest incidence (11 percent) in the upper third group (longest). 

 In addition, 123 females from other collections of both G. huttoni 

 and G. watsoni were examined, and 30 (24 percent) of these varied 

 from the 3-3 formula. The actual distribution of specimens from 

 this last group is as follows: 



This variation seems to occur with similar frequency in the other 

 species of the genus except G. hygoinianus (genital segment of this 

 species has no spines) . 



There is considerable variation in the configuration of the female 

 genital segment within each species (see figs. 48-55). In spite of this 

 variation, the genital segment is of major importance as a taxonomic 

 character for separating females of the genus. 



Similar variation in the characters discussed above also occurs in 

 the Atlantic species {G. ornatus and G. americanus) and it was felt 

 that no purpose would be served in repeating the same analysis on 

 them. Preliminary investigation showed that the results would 

 be essentially the same. 



Males also showed some variation in the aforementioned characters 

 but to a lesser degree. 



