18 
Marianne E. Filka and Rowland M. Shelley 
collected from a diverse array of habitats on each trip. Continuous 
breeding and maturation throughout the year is suggested by these data. 
Two species of Narceus occur in North Carolina; N. americanus , 
known to range throughout the southeastern United States, and N. 
annularis (Rafinesque), known from the northeastern and midwestern 
United States (Chamberlin and Hoffman 1958). Both are reported from 
the mountains (Keeton 1960) and eastern Piedmont (Shelley 1978) of 
North Carolina. 
In his monograph on the Spirobolidae, Keeton (1960) distinguished 
between N. annularis and N. americanus by a formula computing values 
based on somatic features (see footnote Table 1 for explanation) and by 
comparison of gonopodal characters. He found that differences were dif- 
ficult to define due to overlap of characters. Consequently, identifica- 
tions are difficult and distinctions between the species are vague, facts 
corroborated by the Kings Mountain material. 
Thirty-four adults were collected but only 22 of these, 16 males and 6 
females, were in sufficiently good condition for detailed study. As shown 
in Tables 1-2, the number of segments, clypeal setae, and labral setae of 
the Kings Mountain spirobolid are closer to the values for N. americanus: 
but the mean number of ocelli is closer to that for N. annularis. Mean 
length and width, the length/width ratio, and the formula value, also are 
nearer the figures for N. americanus. 
The distal prefemoral endite of the posterior gonopod, normally 
rounded in N. annularis and acute in N. americanus, is rounded in 72% of 
the specimens (Figs. 13-14, pe) and acute in the rest (Fig. 15, pe). 
Likewise, the cephalic groove on the coxal lobes of the third pair of legs 
of males, a characteristic of N. americanus, is absent from all Kings 
Mountain males (Fig. 16). Furthermore, the third coxal lobe of adult 
females, enlarged in N. americanus but only slightly produced ventrad in 
N. annularis, conforms to the latter condition in all but one specimen 
(Figs. 17-19). The Kings Mountain spirobolid therefore could be iden- 
tified as either species of Narceus depending upon the character used, and 
the question becomes one of the relative importance of the characters. 
Although gonopods are the most important taxonomic character in 
the Diplopoda, many genera show few specific gonopodal differences 
whereas there is wide variation in body forms. This appears to be the 
situation in Narceus, and the few gonopodal similarities between the 
Kings Mountain spirobolid and N. annularis do not seem to outweigh the 
close agreement of nearly all the somatic features with those of N. 
americanus. Thus, the Kings Mountain spirobolid is identified as N. 
americanus. The great variability of the somatic features of Narceus, as 
demonstrated by Keeton (1960) and our tables, indicates a need for 
reassessment of the status of the two nominal eastern species. Such a 
study might show them to be conspecific. 
