ISOPODS OF NORTH AMERICA. 



621 



The abdomen is as wide as tlie thorax. The first two segments have 

 the hiteral ])arts covered i)y the hist thoracic segment. The sixth or 

 terminal segment is triangidar, with apex produced to a long, narrow 

 process rounded at the extremity. The terminal segment is 2 mm. 

 wide at the base and li nun. long. The peduncle of the uropoda 



Fig. 670.— Porcellio spinicornis. a, Maxilliped. x 33. b. Second maxilla, x 33. c, First max- 

 illa (OUTER LOBE), rf, MANDIBLE. X 33. €, SECOND ANTENNA. 



extends almost to the extremity of the terminal segment of the body. 

 The inner branch extends a very short distance beyond the terminal 

 abdominal segment. The outer branch is about twice as long as the 

 peduncle. The whole surface of the body is closely covered with 

 small tubercles. 



All the legs are ambulatory. 



PORCELLIO SCABER Latreille. 



Porcellio scaber Latreille, Hist. Crn.st. Ins., VII, 1804, p. 45; Gen. Crust., I, 



1806, p. 70.— Leach, Edinb. Encycl., VII, 1814, p. 406.— Risso, Crust, de 



Nice, 1816, p. 155. 

 OniscuK granulatus La.marck, Hist. Nat. des animaux sans vertebres, V, 1818, p. 



154. 

 Porcellio nigra Say, Journ. Phil. Acad. Nat. Sci., I, 1818, p. 432. 

 Porcellio granulatus Brebisson, Mem. Soc. Calv., 1825, p. 261. 

 Porcellio scaber Desmarest, Consid. Crust., 1825, p. 321. — Brandt and Ratze- 



BURG, Med. ZooL, II, 1830-18.34, p. 77, pi. xii, figs. 1-4 and A-B.— Brandt, 



Bull. Soc. Imp. de. Naturalistes de Moscou, VI, 1833, p. 14. 

 Porcellio brandtn Milne Edwards, Hist. Nat. des. Crust., Ill, 1840, p. 168. 

 Porcellio granulatus 'MiL^E Edwards, Hist. Nat. des Crust., Ill, 1840, p. 169, pi. 



XXXII, fig. 21. 

 Porcellio scaber Milne Edwards, Cuvier Rg. An., 1849, pi. lxxi-lxxi bis. 

 Porcellio nigra Gould, Rep. Invert. Mass., 1841, p. 337. 

 Porcellio scaber Koch, Deutschlands Crust., 1835-1844, p. 34. 

 Porcellio dubius Koch, Deutschlands Crust., 1835-1844, p. 34. 

 Porcellio scaber Lereboullet, Mem. Strasb., IV, 1853, p. 34, pi. i, figs. 4, 5; pi. 



II, figs. 43-47. 

 Porcellio gemmalatus Dana, Crust. U. S. Expl. Exp., XIV, 1853, p. 725, pi. xlvii, 



fig. 7.— Stimpson, Bost. Journ. Nat. Hist., VI, 1850-1857, p. 506. 

 Philoscia tuberculata Stimpson, Proc. Cal. Acad. Sci., I, p. 1856, p. 97. 



