INSECTA APTERA. 3 



seems a Podurid, with affinities to the Entomobryidae, just as the Anurophorinae 



^— which include that remarkable Antarctic genus Cryptopygus (Willem, 1902) are 



Entomobryids, with affinities to the Poduridae. The presence of such ancient 

 connecting links on the Antarctic Continent and islands might reasonably have been 

 expected. 



I have pleasure in naming the type-species of Gomphiocephalus after Mr. 

 T. V. Hodgson, of the ' Discovery.' 



Gomphiocephalus hodgsoni. 



Length, 1 mm. Colour dark blue-violet. Feelers rather shorter than head; 

 proportional length of segments 8 : 11 : 12 : 15. Foot with three long, slender 

 tenent hairs ; claw simple without teeth ; empodium vestigial. Anal spines nearly 

 as long as foot-claw, on short contiguous papillae. 



Habitat. In moss {Bryum algens, Cardot *), Granite Harbour, South Victoria Land. 

 (Types in British Museum.) 



The whole insect is of a very deep blue-violet colour. The cuticle is finely 

 rugose, and bears numerous bristles, many of which, especially on the terminal 

 abdominal segments, are elongate, but none are feathered. The general aspect of the 

 species and the form of the foot are suggestive of a Xenylla. 



Feelers. The feelers (figs. 1, 2) have characteristic sense-organs both on the 

 third and fourth segments. On the dorsal- aspect of the extremity of the third 

 segment is a group of four short, sharp spines arising from large circular depressions in 

 the cuticle, and surrounded by a sinuous ridge (fig. 1, d). The two outer spines of 

 this organ are stronger than the two central. At the tip of the fourth segment is a 

 long tapering sensory bristle (fig. 1, h), and near it is a sub-apical sense-organ (fig. 1, a) 

 consisting of an oval depression within which is placed a slender bristle. Close to this 

 are two small rounded papillae with a bristle at the tip of each. At the apex of the 

 fourth segment and directed ventralwards, a bladder-like protrusible organ (fig. 2, c) 

 can be seen in two specimens. 



Cephalic sense-organs. The most careful search has failed to discover any 

 trace of ocelli, and I believe that they are absent. In every specimen, however, the 

 post-antennal organ (fig. 1, e) is prominent — a simple chitinous ridge of oval or heart- 

 shaped form, varying in the details of its outline in diff'erent specimens («' e"). Behind 

 this is a structure, which appears to be a sense-organ, hitherto undescribed, as I believe, 

 in any springtail. It is a stout curved tooth-like outgrowth (fig. 1, /), probably 

 performing a tactile function in connection with the shelters beneath which these 



insects live. 



Jaws. The front region of the head is distinctly produced towards the mouth, 

 producing the " prognathous " aspect which characterises this group of CoUembola. 



* See these Beports, vol. iii. ; Musci, p. 5. 



P 



