J99 



COLLEMBOLA. u f a,. 



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By Geo. H. Carpenter, B.Sc. Lond., M.R.I.A. ""'"'^^."^ 

 (Plate IX.) 



The Collembola or Springtails are insects whose wingless condition is apparently 

 primitive ; they differ from the Thysanura or Bristletails, the other division of the 

 Aptera, in having only six evident abdominal segments, to the fourth of which belongs 

 the peculiar saltatory organ, formed by the partial fusion of a pair of appendages and 

 known as the "spring." The maxillulae — a small pair ot jaws between the mandibles 

 and maxillae — are fairly well developed in the Collembola as in the Thysanura ; in the 

 winged insects these jaws are always vestigial or absent. 



Nothing has been hitherto published on the Collembola of the Sandwich Islands. 

 Indeed very little is known of these insects outside Europe and North America. 

 Therefore, although the five species described in the present paper appear to be peculiar 

 to the Sandwich Islands, it is not impossible that some of them may yet be found in 

 other parts of the world, or may be shown, by the discovery of connecting links, to be 

 not distinct specifically from other forms. All of the species belong to large and 

 widespread genera, and four of them have been found each on but one of the islands. 

 The fifth, which is the only representative of the family Achorutidae, occurs both in Oahu 

 and in Maui. 



Two of the three families of Collembola are represented in the collection, the most 

 highly specialized family, the Sminthuridae, characterised by their sub-globular abdomen 

 with indistinct segmentation, being absent. The two families to be dealt with are 

 easily separated as follows : 



Spring well-developed; body scaled or not scaled Entomobryidae. 



Spring vestigial or absent ; body never scaled Achorutidae. 



The Achorutidae are represented by one species only. Three genera ot Entomo- 

 bryidae are present, which may be distinguished thus : 



Fourth segment of abdomen nearly the same length as the third Isotoma. 



Fourth segment of abdomen at least three times as long as the third. 



Body covered with scales Lepidocyrtus. 



Body without scales Entomobrya. 



