North Carolina Terrestrial Isopods 5 



13b. With no broad projection on anterior margin of head (Fig. 



30) (black or yellow-brown) Armadillidium vulgare 



14a (12). Does not roll into ball 15 



14b. Rolls into ball (black) Cylisticus convexus 



15a (14). Head relatively smooth 16 



15b. Head strongly tuberculate (Fig. 22) (brown) 



Porcellio scaber 

 16a (15). Posterior margin of thoracic segment I straight; pleotelson 



triangular (Fig. 24) (gray) Porcellio laevis 



16b. Posterior margin of thoracic segment I recurved laterally; 



pleotelson produced into point 17 



17a (16). Proximal article of flagellum longer than distal article; 



exopod of pleopod 1 of male with small spines (reddish- 

 brown — frosted) Porcellionides pruinosus 



17b. Proximal article of flagellum about as long as distal article; 

 exopod of pleopod 1 of male with large spines (Fig. 27) 

 (brown) Porcellio virgatus 



SPECIES DISCUSSIONS 



Ligia exotica Roux 

 Figs. 1,2 

 Ligyda exotica (Roux). Richardson 1905:676, figs. 716-718. 

 Ligia exotica Roux. Van Name 1936:48, fig. 8. Stephenson and Ste- 

 phenson, 1952:29. 

 Ligia sp. Harger 1878:310. 



Harger's 1878 record of Ligia sp. from Ft. Macon most probably is 

 the first record of the species from North Carolina. Richardson (1905) 

 recorded it from nearby Beaufort and it is here recorded from around 

 Beaufort and at Cape Hatteras. The species is abundant on rocky jetties, 

 piers, and other hard substrates, both natural and man-made, from 

 Florida to Virginia and perhaps north to New Jersey. If relatively cool 

 daytime retreats are present the nocturnally active species can be very 

 abundant at any site. The species is also present along the margin of salt 

 water bays and estuaries, which are so prevalent on the North Carolina 

 coast, but details of its habitats along these margins have never been 

 studied. Gravid females were collected in August and September, but 

 they probably are present from early summer until fall. The species is 

 distinguished from others with which it might be confused by the con- 

 figuration of the apex of the endopod of male pleopod 2 (Fig. 2). Spec- 

 imens, especially in autumn, range up to 32 mm long. Published records 

 of the species in North Carolina are plotted on Map 1, but it is undoubt- 

 edly present in many suitable habitats along most of the coastline of the 

 state. 



