130 BULLETIN 168, UNITED STATES NATIONAL MUSEUM 



Plate 4 

 Fohomia silvestrii: 



35. Eyes and postantennal organ of right side, X 594. 



36. Outline of eye patch, postantennal organ, and first antenna! segment of 



right side, X 594. 



37. Right hind foot, X 929. 



38. Right aspect of dens and mucro, X 594. 



39. Dorsal setae of first abdominal segment, X 453. 

 Folsomia elongata: 



40. Eyes and postantennal organ of right side, X 937. 



41. Sense organ of third antennal segment of right side, X 941. 



42. Left hind foot, X 576. 



43. Left dens and mucro, X 564. 



44. Right mucro, X 970. 



45. Abnormal left mucro, X 847. 



46. Dorsal setae of first abdominal segment, X 347. 



Plate 5 

 Folsomia guthriei: 



47. Eyes and postantennal organ of right side. From Guthrie. 



48. Right aspect of furcula. From Guthrie. 



49. Mucro. From Guthrie. 

 Folsomia sexoculata: 



50. Eyes of left side, X 594. 



51. Left fore foot, X 594. 

 Folsomia quadrioculata: 



52. Eyes and postantennal organ of left side, X 594. 



53. Sense organ of third antennal segment of right side, X 970. 



54. Right hind foot, X 594. 



55. Portion of furcula, X 347. 



56. Left dens and mucro, X 347. 



57. Left mucro, X 747. 



58. Dorsal setae of second abdominal segment, X 347. 



Plate 6 

 Folsomia diplophthalma: 



59. Eye and postantennal organ of right side, X 735. 



60. Eye and postantennal organ of right side, X 758. 



61. Sense organ of third antennal segment of right side, X 1,260. 



62. Right fore foot, X 952. 



63. Left hind foot, X 952. 



64. Right dens and mucro, with manubrial teeth showing through the dens, 



X 570. 



65. Manubrial teeth, in ventral aspect, X 735. 



66. Mucro, X 1,026. 



67. Dorsal setae of first abdominal segment, X 570. 



Plate 7 

 Folsomia fimetaria: 



68. Postantennal organ of left side, X 576. 



69. Postantennal organ and first antennal segment of left side, X 465. 



70. Postantennal organ and base of first antennal segment of right side, 



X 465. Specimen from New Jersey. 



71. Postantennal organ and first antennal segment of left side, X 465. 



Specimen from Illinois. 



