COLLEMBOLA OF THE FAMILY ISOTOMIDAE 45 



14. Manubrium with one pair of ventral subapical setae. Genital 



and anal segments almost always ankylosed 15 



Manubrium with three pairs of ventral subapical setae. Genital 

 and anal segments not ankylosed. One tenent hair. White, 

 mottled with gray or black simplex (p. 61) 



15. Eyes 16 16 



Eyes 10. Tenent hairs absent. White decemoculata (p. 60) 



16. Unguis with an inner tooth. Tibiotarsus with a distal subseg- 



ment 17 



Unguis without an inner tooth. Unguiculus untoothed. Ten- 

 ent hairs absent. Genital and anal segments ankylosed 18 



17. Eye spots one on each side. One tenent hair. Mucro relatively 



shorter and stouter, with ventral contour strongly rounded, 



in lateral aspect. Grayish or blackish tenelloides (p. 62) 



Eye spots usually two on each side. Tenent hairs absent. 

 Mucro relatively slenderer, with ventral contour not strongly 

 rounded, in lateral aspect. Genital and anal segments anky- 

 losed. Bluish or greenish gray aquae (p. 59) 



18. Manubrium three-fifths as long as dentes. Teeth of mucro 



subequal. Mucro relatively long, in lateral aspect not strongly 



rounded ventrally. Yellow to purplish constricta (p. 64) 



Manubrium less than half as long as dentes. Apical tooth of 

 mucro larger than the anteapical. Mucro relatively short, 

 in lateral aspect strongly rounded ventrally. Bluish, green- 

 ish, or blackish cognata (p. 65) 



PROISOTOMA (PROISOTOMA) RAINIERI, new species 



Plate 16, Figures 160-168 



Descrijytion. — Olive-green throughout; darker dorsally. Body and 

 appendages stout. Eyes (pi. 16, fig. 160) eight on each side, sub- 

 equal. Postantennal organ (pi. 16, fig. 160) broadly elliptical, from 

 two to three times as long as the diameter of an eye. Antennae one- 

 fourth longer than the head, with segments in relative lengths about 

 as 7:8:8:14. Sense organ of third antennal segment (pi. 16, fig. 161) 

 with a pair of stout curving rods subtended by an evident chitinous 

 ridge. Fourth antennal segment with slender strongly curving ol- 

 factory setae. Third and fourth abdominal segments equal in length. 

 Genital and anal segments not ankylosed. Tibiotarsus without a 

 distal subsegment. Unguis (pi. 16, fig. 162) not strongly curving, with 

 a pair of small lateral teeth one third from the base, and without inner 

 teeth. Unguiculus (pi. 16, fig. 163) extending two-thirds as far as 

 unguis, sublanceolate, untoothed, with a pair of rounded inner 

 lamellae. Tenent hairs absent. Furcula appended to the fifth ab- 

 dominal segment, extending about as far as the ventral tube. IMa- 

 nubrium: dens: mucro as 36:56:5. Manubrium subcylindrical, with 

 many short dorsal setae and three small subapical ventral setae. 

 Dentes (pi. 16, fig. 164) stout, sUghtly narrowing distally; with many 

 coarse hemispherical dorsal tubercles, larger proximally and gradually 

 becoming smaller distally; with many ventral setae, numerous short 



95462—37 4 



