Cakpenter — The Apterygota of the Seychelles. 83 



(see fig. 7), whereas in Borner's specimens these segments are described and 

 figured (p. 147, fig- 1) as of ahnost equal length. The presence of minute 

 secondary segments or "jointlets" between the second and third and third 

 and fourth antennal segments (see fig. 9) is noteworthy. This feature is 

 mentioned by Folsom in his description of A. nitida. 



Locality. — Aldabra, from algae, Bassin Cabris, Picard Island. (J. C. F. 

 Fryer, coll. 9th April, 1909.) 



On account of the exceptional interest of this species, figures are given of 

 the leading structural features of the Aldabra specimens, that it may be seen 

 how closely they agree with Borner's types. The details shown in Folsom's 

 drawings of his Japanese species nitida (in which the third abdominal 

 segment is longer than the fourth) agree also very closely with A. thalassojihila, 

 and it is possible that we have but forms of one widespread species, with a 

 tropical and sub-tropical range analogous to that of not a few northern 

 Collembola with littoral habitat. The Japanese localities mentioned by 

 Folsom (Tokyo and Niyagi) are apparently, however, not maritime. The 

 geographical relations of shore-haunting insects are especially interesting ; a 

 discussion on these is given below (p. 49). 



In his remarks on Axelsonia, Borner (I.e. p. 150) expressed his opinion 

 that the simple form of the bothriotricha in the genus gives it a position 

 intermediate between the characteristic Isotomini and the Isqtomurini. He 

 adds: "Ob sie ein Glied der Isotomini C.B. oder der Isotomurini C.B. ist, 

 lasst sich schwer entscheiden und bleibt moglicherweise stets dem subjektiven 

 Ermessen [!] der Forscher iiberlassen." After this admission it is somewhat 

 surprising that he continued to argue for the decisive evidence of the 

 bothriotricha as a character for placing the Isotomurini along with the 

 Entomobryinae. Further on he pointed out that from the presence of 

 bothriotricha in certain Poduridae and Sminthuridae, " ist ihre Entstehung 

 zur Zeit der hypothetischen ProtoeoUembola hochst wahrscheinlich." Surely 

 if this be so, and the presence or absence of these bristles is useless as a 

 family character, it should not have been allowed to override the many 

 important and conspicuous features of structure which led systematists, 

 until a few years ago, to include Isotomurus and Axelsonia in the compre- 

 hensive genus Jsotoma. While objecting to Borner's classification as 

 unwarranted and highly inconvenient, I felt in full agreement with him in 

 regarding Axelsonia as "tief an der Wurzel des ganzen Entomobryenstammes " 

 — an additional argument indeed for considering it to be nearly related to 

 typical Isotoma. And now the discovery that these spring-tails have no 

 " trochanteral organs " leads Borner, as stated above, to replace the insects 

 where this obvious relationship is emphasized. 



B.I, A. PROC, VOL. XXXUl, SECT. B. [F ] 



