92 BULLETIN 168, UNITED STATES NATIONAL MUSEUM 



of dense short stiff setae, unequal in length; erect sensory setae simple, 

 not much longer than the other setae. Length, 0.9 mm. 



Remarks. — There is some variation in the form of the mucro, 

 particularly in the size of the anteapical tooth, as shown in plate 29, 

 figures 333 to 336. 



My specimens agree with a cotj^pe in the Museum of Comparative 

 Zoology, Cambridge, Mass., and with a cotype received from Mac- 

 Gillivray. 



This species occurs in or near the soil. I have found it to be 

 rather common under damp logs lying on the ground, or under the 

 loose bark of logs, and have taken it abundantly in pastures in 

 decaying manure. 



Distribution. — Kecorded as follows: 



Massachusetts: Arlington, May. 



New York: Rochester, March 9, E. A. Maynard. 



Ohio: Salineville, A. D. MacGillivray (Museum of Comparative Zoology). 



Illinois: Champaign, March 13, 16, 17, 19. Homer, April 2, 17, 24, 27, 29, 



May 3, 13, October 10, 15. 

 Louisiana: Baton Rouge, March 9, in cane trash, C. L. Stracener. 



ISOTOMA aSOTOMA) EUNOTABILIS, new species 



Plate 29, Figures 337, 339; Plate 30, Figures 340-344 



Description. — General color grayish, greenish, or bluish. Head 

 and body finely mottled with bluish-gray pigment interrupted by 

 closely set, rounded, pale spots. Body segments narrowly bordered 

 posteriorly wdth blackish. Eyes connected anteriorly by a narrow 

 A-shaped mark. Legs and furcula pale. Antennae pale, with seg- 

 ments more or less purplish distally. Young individuals may be 

 white, with minute specks of blackish pigment. Eyes four on each 

 side, equal, arranged as in plate 29, figure 337, on a small roundish 

 black patch. Postantennal organ (pi. 29, fig. 337) relatively large, 

 elliptical, close to eyes, three to four times as long as the diameter 

 of an eye. Antennae longer than the head (as 1.5:1), with segments 

 in relative lengths about as 10:16:16:33. Sense organ of third an- 

 tennal segment with a pair of small, slightly curving rods, subtended 

 by a chitinous ridge. Fourth antennal segment with a few stout, 

 slightly curving olfactory setae. Unguis (pi. 29, fig. 339) simple, 

 without lateral or inner teeth. Unguiculus extending half as far as 

 the unguis, broadly sublanceolate, pointed, untoothed. Tenent hairs 

 absent. Third abdominal segment slightly shorter than the fourth 

 (as 28:33). Genital and anal segments ankylosed, with often a trace 

 of the dorsal suture. Furcula appended to the fifth abdominal seg- 

 ment, extending to tlie ventral tube. Manubrium much shorter 

 than dentes (as 6:17), with many stiff setae on all sides. Dentes 

 slender, gradually tapering, crenulato dorsally, with many ventral 

 setae and a few erect dorsal proximal setae. Mucro (pi. 30, figs. 



