110 BULLETIN 168, UNITED STATES NATIONAL MUSEUM 



p. 116; 1924b, p. 74; 1925a, p. 232; 1928a, p. 542; 1928c p. 128; 1929, p. 67.— 



WoMERSLEY, 1924a, p. 32; 1924b, p. 169; 1927, p. 376; 1928, p. 62.— Remy, 



1928, p. 64. 

 Isotoma caerulea Bourlet, 1839, p. 401. — Gervais, 1844, p. 433. 

 Desoria virescens Nicolet, 1841, p. 59. — Gervais, 1844, p. 428. 

 Desoria cylindrica Nicolet, 1841, p. 60. — Gervais, 1844, p. 429. 

 Desoria viatica Nicolet, 1841, p. 61. — Gervais, 1844, p. 429. 

 Desoria pallida Nicolet, 1841, p. 61.— Gervais, 1844, p. 430. 

 Desoria ebriosa Nicolet, 1841, p. 61. — Gervais, 1844, p. 430. 

 Desoria annulala Nicolet, 1841, p. 61. — Gervais, 1844, p. 430. 

 Podura viridis Bourlet, 1841-2, p. 114. 

 Podura annulata Bourlet, 1841-2, p. 117. 

 Heterotoma chlorata Gervais, 1844, p. 421. 

 Isotoma desmarestii Gervais, 1844, p. 436. 

 Isotoma virescens Nicolet, 1847, p. 372. 

 Isotoma cylindrica Nicolet, 1847, p. 372. 

 Isotoma viatica Nicolet, 1847, p. 373. 

 Isotoma ebriosa Nicolet, 1847, p. 373. 

 Isotoma annulata Nicolet, 1847, p. 373. — Lubbock, 1873, p. 175. — Parona 



1882, p. 463. 

 Isotoma anglicana Lubbock 1873, p. 171. 

 Isotoma palustris Tullberg, 1871, p. 151; 1872, p. 45; 1876, p. 34. — Uzel, 1890, 



p. 62. 

 Isotoma belfragei Packard, 1873, p. 33. — MacGillivray, 1891, p. 273 

 Isotoma tricolor Packard, 1873, p. 34 (part). — MacGillivray, 1891, p. 274 



(part) . 

 Isotoma purpurascens Packard, 1873, p. 34. — MacGillivray, 1891, p. 274. 

 Isotoma plumbea Packard, 1873, p. 35. — MacGillivray, 1891, p. 274. 

 Isotoma capitola MacGillivray, 1896, p. 56. 

 Isotoma glauca MacGillivray, 1896, p. 57. 



Description. — Color very variable: dark green, greenish yellow, 

 dull yellow, lilac, blackish blue, reddish purple, leaden purple or 

 dark brown; usually with small pale dorsal spots (pi. 37, fig. 428). 

 Body segments often banded posteriorly with dark pigment. With- 

 out strong longitudinal lines in the typical form. Eyes (pi. 37, fig. 

 429) eight on each side, subequal. Postantennal organ (pi. 37, 

 fig. 429) broadly elliptical, oval or round; shorter, to a little longer, 

 than the diameter of an eye. Antennae one and one-half to two 

 times as long as the head, Avith segments in relative lengths about 

 as 4:7:7:8. Sense organ of tliird antennal segment (pi. 37, fig. 430) 

 consisting of a pair of slender rods, freely exposed. Abdominal 

 segments without ankylosis (pi. 38, fig. 441). Fourth abdominal 

 segment slightly shorter than the third. Unguis (pi. 37, figs. 431- 

 433) long, slender, slightly curving, with a pair of large lateral teeth, 

 with inner margin bidentate, and with parallel basal folds. Unguic- 

 ulus extending two-fifths to two-thirds as far as the unguis, lance- 

 olate, unidentate near the middle of the inner margin. Tenent hairs 

 absent. Furcula appended to the fifth abdominal segment, strongly 

 developed, attaining the ventral tube. Dentes more than twice as 

 long as the manubrium, slender, gradually tapering, crenulate dor- 



