North Carolina Terrestrial Isopods 3 



DEFINITIONS 



The following terms are used in the key and discussions. They will 

 be helpful to the non-specialist. 



FLAGELLUM — thin apical part of antenna 2 divided into two or 

 more ARTICLES. 



OCELLUS — unit of eye (compound eye has two or more ocelli); the 

 eye can have one to many ocelli in isopods. 

 UROPODS — posterior appendages ("tails" in some species). 

 PLEOPODS — appendages of ABDOMEN (pleon), or posterior five 

 segments plus pleotelson of body. Each pleopod has an EXOPOD 

 (outer branch) and an ENDOPOD (inner branch). Both branches of 

 pleopods 1 and 2 (the first and second small appendages behind the 

 seventh pair of walking legs) are sexually modified in male oniscoids. 

 The endopod of each of the pleopods usually is elongate and serves as a 

 secondary sexual organ. Males can be distinguished from females by 

 the presence of these modified pleopods. 



PLEOTELSON — sixth abdominal segment, fused with telson (last 

 body segment) and with uropods as appendages. 



THORAX (peraeon) — main seven segments of body behind head, in 

 front of abdomen. 



EPIMERE — lateral extensions of thoracic and abdominal segments in 

 oniscoids. 



PROCESS— a projection. 

 TUBERCULATE— with small bumps. 



Van Name (1936) included a general account of the morphology of 

 terrestrial isopods in his introduction. 



KEY TO SPECIES OF TERRESTRIAL ISOPODS 

 OF NORTH CAROLINA 



All 18 species of oniscoids so far recorded within the borders of 

 North Carolina are included here. Certain species not yet recorded also 

 might be present. Specimens of such species could be erroneously identi- 

 fied by using only "key" characters, so comparison of specimens with 

 illustrations (especially the pleopods) is essential. Specimens not fitting 

 the key perhaps can be identified by use of the comprehensive works of 

 Van Name (1936, 1940, 1942). Color is a useful character for identifying 

 freshly caught isopods, but color fades on preservation and is only of 

 limited value as an aid for identifying preserved specimens. Color 

 phases also are common in populations of some species. Base color (all 

 species are multicolored) is included in parentheses in the key. 



Many people think that tiny or small isopods are the young of 

 larger species. This might be true, especially in spring and early summer, 

 but some small specimens are distinct species and live in association 

 with larger specimens of other species. Specimens of all sizes then must 



