x ISOPODS OF NORTH AMERICA. 609 



Color dark brown, covered with numerous white spots or little 

 stripes. Legs yellow, with the coxvs spotted with black. 

 Length, 9 mm.; width, 4 mm.; height, 1.6 mm. a 



1O8. Genus CYLISTICUS Schnitzler. & 



Body oblong, very convex, contractile into a ball. 



Head with lateral lobes distinct; median lobe small; front of head 

 marginate. Eyes distinct, lateral. Second pair of antennae long; fla- 

 gellum composed of two subequal articles. 



Lateral parts of the thoracic segments large. 



Abdomen not abruptly narrower than thorax; lateral parts of third, 

 fourth, and fifth segments well developed; terminal segment conically 

 produced. 



Opercular plates of all the pleopods furnished with tracheae. 



Inner branch of the uropoda inserted far in front of the outer branch, 

 near the inner antero-lateral angle of the peduncle. 



CYLISTICUS CONVEXUS (De Geer). 



Oniscus convexus DE GEER, Mem. des Insectes, VII, 1778, p. 553, pi. xxxv, fig. 11. 

 Porcellio spinifrons BRANDT, Bull, de la Soc. Imp. d. Naturalistes de Moscou, VI, 



1833, p. 15. 



Porcellio Isevis KOCH, Deutschlands Crustaceen, 1835-1844, p. 6. 

 Porcellio armadilloides LEREBOI:LLET, Mm. de la Soc. du Museum d'Histoire Nat. 



de Strasbourg, IV, 1853, p. 65, pi. i, fig. 18; pi. in, figs. 88-94. 

 Cylisticus Ixvis SCHNITZLER, De Oniscineis agri Bonnensis, 1853, p. 25. 

 Porcellio armadilloides KINAHAN, Nat. Hist. Rev., IV, 1857, p. 279. 

 Porcellio convexus JOHNSON, Academisk Afhandling, Upsala, 1858, p. 32. 

 Porcellio armadilloides BATE and WESTWOOD, Brit. Sessile-eyed Crust., II, 1868, 



p. 485. 

 Porcellio convexus BUDDE-LUND, Nat. Tidsskr. (3), VII, 1870-71, p. 240. STUX- 



BERG, Ofvers. af Kgl. Vetenskaps Akad. Forh., 1875, p. 60. 

 Cylisticus convexus BUDDE-LUND, Crust. Isop. Terrestria, 1885, pp. 77-79. (See 



Budde-Lund for further synonymy.) G. O. SARS, Crust, of Norway, II, 



1899, p. 186, pis. xi, xii. RICHARDSON, Amer. Nat., XXXIV, 1900, p. 303; 



Proc. U. S. Nat. Mus., XXIII, 1901, pp. 565-566. STOLLER, 54th Report 



New York State Museum, 1902, p. 213. PAULMIER, Bull. New York State 



Museum, 1905, pp. 181-182. 



The above description is adapted from the following one of Budde-Lund's: 



Oblonge ovalis, convexiuscula, nitida, tenuiter et sparse punctata. 



Antennae exteriores . . . 



Linea marginalis frontalis recta; epistoma medio linea transversa. 



Cauda trunco abrupte angustior; epimera subdistantia. Annulus analis brevis, 

 subtriangulus, lateribua subrectis vel leviter incurvis, apice obtuso, supra sulcatus. 



Color ex nigro brunneus, maculis vel striolis numerosis albidis conspersus. Pedes 

 flavi, coxis nigromaculatis. 



Longitudo, 9 mm.; latitude, 4 mm.; altitude, 1.6 mm. BUDDE-LUND, Crust. Isop. 

 Terrestria, 1885, pp. 210-211. 



6 For characters of genus see Budde-Lund, Crust. Isop. Terrestria, 1885, p. 77, 

 and Sars, Crust, of Norway, II, 1899, p. 185. 

 2858905 39 



