COLLEMBOLA OF THE FAMILY ISOTOMIDAE 131 



72. Sense organ of third antennal segment of right side, X 988. 



73. Right hind foot, X 467. 



74. End of abdomen, showing ankylosis of last three segments, X 100. 



75. Ventral aspect, for comparison with figure 74, X 100. 



76. Left mucro, X 576. Specimen from Europe. 



77. Left mucro, X 576. Specimen from Massachusetts. 



78. Left aspect of tenaculum, X 200. 



79. Dorsal setae of first abdominal segment, X 306. 



Plate 8 

 Folsomia fimetaria caldaria: 



80. Right hind foot, X 808. 

 Folsomia nivalis: 



81. Left postantennal organ, X 1,344. 



82. Postantennal organ and first antennal segment of right side, X.560. 



83. Sense organ of third antennal segment of left side, X 1,344. 



84. Left fore foot, X 1,152. 



85. Left mucro and end of dens, X 1,320. 



86. Left mucro and end of dens, X 1,152. 



87. Left mucro, X 1,152. 



88. Abnormal left mucro, X 1,040. 



Plate 9 

 Guthriella antiqua: 



89. Specimen, X 102. 



90. Eyes and postantennal organ of right side, X 434. 



91. Sense organ and third antennal segment of left side, X 1,043. 



92. Left hind foot, X 788. 



93. Right hind unguiculus, X 987. 



94. Manubrial hooks, ventral aspect, X 627. 



95. Dentes and mucrones, X 306. 



96. Left mucro, X 900. 



97. Right mucro, X 900. 



98. Dorsal aspect of right mucro, X 987. 



99. Dorsal setae of third abdominal segment, X 627. 



Plate 10 

 Guthriella vetusta: 



100. Eyes and postantennal organ of left side, X 480. 



101. Sense organ of third antennal segment of left side, X 1,185. 



102. Left hind foot, X 757. 



103. Left dens and mucro, X 435. 



104. Left mucro, X 1,185. 



105. Right mucro, oblique-dorsal aspect, X 1,185. 



106. Dorsal setae of first abdominal segment, X 435. 



Plate 11 

 Guthriella muskegis: 



107. Female, X 27. 



108. Male, X 28. 



109. Postantennal organ and adjacent eye of right side, X 1,053. 



110. Left hind foot of female, X 487. 



111. Left mucro of female, X 507. 



112. Right mucro of female, X 507. 



