INSECTA APTBEA. 5 



Spring and Catch. Most of the specimens examined show no trace of these 

 structures, but in two the appearance drawn in fig. 1 1 can be plainly seen. The spring 

 (fig. 11, s) is clearly in a vestigial condition, its manubrium being merged in the ventral 

 region of the fourth abdominal segment, while the combined dens and mucro terminate 

 in a blunt, rounded knob. 



The catch (retinaculum) is represented by a pair of small rugose prominences 

 (fig. 11 r) on the third abdominal segment. 



Anal Spines. The anal spines are nearly as long as the foot-claw, slightly and 

 evenly curved (figs. 11, 12). They are situated on short, contiguous papillae. In all 

 the specimens examined the spines are slightly asymmetrical (fig. 12), but this is 

 probably due to the position of one having been slightly shifted. 



EEFERBNCES. 



• 



1906. 'C. BoENBE. Das System der CoUembolen nebst Beschreibung neuer Collembolen des Hamburger 



naturhistoriscben Museums. 2 Beiheft zum Jahrl. der Hamburg, wissensch. Anstalten, xxiii., 



1906, pp. 147-188. 

 1902. G. H. Caepbntee. " Insecta Aptera," in Report on Collections, Voyage of Southern Cross, 



pp. 221-3, pi. xlvii. London (British Museum), 1902. 

 1906. Scottish National Antarctic Expedition. ' Scotia ' Collections. Collembola 



from the South Orkney Islands. Proc. Royal Soc. Edinb., xxvi., 1906, pp. 473-483, pis. 1-2. 



1906. E. Wahlgeen. Antarktische und subantarktische CoUembollen gesammelt von der schwedischen 



• Siidpolarexpedition. Wissensch. Ergebn. der Schwed. SUdpolarexpedition, 1901-3, vol. v., 



1906, pp. 1-22, pis. 1-2. 

 1902. V. WiLLBM. Collemboles : Resultats du Voyage de S. T. 'Belgica' en 1897, 1898, 1899. 



Scientifigues. Anvers, 1902. 



EXPLANATION OF PLATE. 



Gomphiocephdlus hodgsoni. 



Fig. 1. — Left feeler with part of head, dorsal aspect ; a, sub-apical, depressed sense-organ ; b, sensory 

 bristle ; d, sensory spines on third antenn.al segment ; e, post-antennal organ ; /, dentiform 

 cephalic sense-organ ; e', e", variations in form of post-antennal organ from other specimens. 



Fig. 2.— Eight feeler, lateral aspect of extremity ; a and d as in fig. 1 ; c, apical, protrusible sense-organ. 



Fig. 3. — Left mandible, seen from inner aspect. 



Fig. 4. — Left mandible, dorsal aspect. 



Fig. 5. — Eight maxillula, showing teeth and molar area. 



Fig. 6. — Left maxilla ; s, stipes ; g, galea ; I, lamellae ; p, palp. 



Fig. 7. — Second pair of maxillae forming labium. 



Fig. 8. — Labrum. 



Fig. 9. — Eight hind leg, showing claw, vestigial empodium, and tenent hairs on foot. 



Fig. 10. — ^Ventral tube on first abdominal segment, seen from right side. 



Fig. 11.— Part of hind abdominal segments, showing anal spines, and vestigial spring (s) and catch (r) ; 

 lateral view. 



Fig. 12.— Tip of abdomen, with papillae and anal spines ; postero-ventral view. 



All figures are magnified 600 diameters. 



