324 Sir J. Lubbock on a new Genus of Collembola. 



extremity rests on the pebble, the entire length has been com- 

 puted by allowing two thirds for the inner and one third for 

 the outer portion, reckoning the total thickness of the sponge 

 from the pebble to the summit of the aculeation as above 

 stated. The position of the vents must also be taken as pro- 

 visional ; for I have never seen one with an unmistakably 

 defined margin and only the " tubular prolongations " above 

 mentioned, which, having been broken off at the extremities, 

 may after all not have been tubularly prolonged vents. 



In several sponges there is a subskeleton-spicule, which 

 presents two or three spines at one or both ends {ex.gr. PI. XV. 

 figs. 25, hj 29, J, and 28, a), which so far are like the fissurate 

 ends of the spicule in HymerapMa verticillata ; and this often 

 passes into ends which are inflated and spined all over in 

 other species. The remarkable spiculation of HymerapMa 

 verticillata has necessitated this long description. 



[To be continued.] 



XXVIII. — On a new Genus and Species of Collembola from 

 Kerguelen Island. By Sir JoHN LuBBOCK, Bart., M.P. 



Among the Thysanura submitted to me by Mr. Eaton was a 

 form of the Lipuridce^ which I propose to dedicate to M. Tull- 

 berg, who has so largely contributed to our knowledge of this 

 group. 



Genus TULLBERGIA, n. g. 



Corpus elongatum. Antennae non clavata?, quadriarticiilatae. Or- 

 gana postantennalia transversa. Unguiculi inferiores nulli. 

 Spinse anales magnse. 



Tullhergia antarctica^ n. sp. 



White (colourless in spirit). Skin granular, and witli scat- 

 tered hairs. Ocelli absent (I could see none). Postantennal 

 organ situated directly behind the antenna ; it has numerous 

 oval tubercles. Feet with only one claw, and without tenent 

 hairs. Anal spines large and strong ; their apex oblique and 

 outwardly prolonged into a somewhat slender triangular point, 

 not acuminate. 



Length 4- inch. 



Hah. Common in wet moss on hill-sides and low ground in 

 the neighbourhood of Observatory Bay, Royal Sound. 



