428 Mr. J. W. Shoebotham's Notes on Collembola. 



1. Head hypognathous. Uyes situated near the hind edge of the 



head. Dentes bowed ia the horizontal plane, annulated 

 towards the end, over-reaching the ventral tube. Manubrium 

 in form recalling that of the Symphypleona, with a special 

 medial support-piece of the dentes, 



1. Family Podurid^ (C. B.), 1906. 



2. Head, obliquely prognathous. With or without eyes, these, if 



present, situated in front of the middle of ihe head. Dentes 

 not annulated, fairly straight, seldom reaching past the 

 ventral tube, or the furcula more or less completely reduced. 

 Wlien the furcula is present the manubrium is simple in 

 form, without the medial support-piece of the dentes. 



2. Family Hypogastrurid^ (C. B.). 



i. Mandibles with well-developed molar plate. 



Subfamily Hypouastrurin^, C. B., 1906. 



il. Mandibles without true molar plate or absent. 



Subfamily AcHORaTiN^, C. B., 1906. 



* Anal segment with undivided supra-anal valve. With or 

 without furcula. 



Tribe Pseudachorutini, C. B., 1906. 



** Annl segment with double-lobed broader supra-anal valve. 

 Without furcula. 



Tribe Achorutini, C. B., 1906. 



b. IVith pseudocelli. Without ej^es. The sense-organ on antenna 

 III. provided with from 2-3 sense-cones, and often at the same 

 time with outer papillfe and protecting bristles, in addition to 

 the sense-rods. Post-autennal organ generally well-developed. 

 Antennal segment 4 generally with subapical sense-pit 

 { = Lipuridee, Lubbock, 1809 '.) 



3. Family Onychiurid.e (Lbk., C. B.). 



II. Tergian of the prothorax ahvays membranous and without hairs. 

 Furcula generally present, and in the move recent forms of the 

 group pushed anahvards. Integument generally smooth, mostly 

 with sclerites. Ventral tube short or elongated, sometimes with 

 a lateral blind sac. Manubrium ventrally, generally with hairs 

 or scales, seldom naked. 



Section ENTOAroBUYOMORPHA, (IB., 1913. 



a. Trochanteral organ absent. Ventral edge of the claw simple, 

 without groove. 



1. Third and fourth abdominal terga of nearly equal length or 

 the 4th longer, sometimes this (the 4th) fused with the 5th 

 and 6th (without scales ^). Naked or ciliated sensory setje 

 (^ = bothrioiriche) present or absent. 



4. Family Isotomid^ (Schflr., C. B., 1896-1903,) 



1 This should be 1870. Lubbock's "Notes on the Thysanura — 

 Part 4," was published in 1870, not 1869.— J. W. S. 



^ This is as given by Biirner (1913 6); but, to include the genus 

 Oncopodura, Carl & Lebed., it should now read " Scales nearly always 

 absent, when present thev are without longitudinal ribs.'' — J. V\\ S., 

 1914. 



