32 12 Proceedings of the Royal Irish Academy. 



1904. Cabpentee, G-. H., and "W. Evans. — Some Springtails new to the British 



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1910. Collinge, W. E., and J. W. Shoebotham — The Apterygota of Hert- 



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1817. Zool. Miscellany, iii. 



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Explanation of Plate I. 



Structural details of Petrobius maritimiis. 

 Fig. 



1. Head of male, front view, showing eyes (c), lateral ocelli (o), median 



ocellus (o.m,.), and labrum; also basal, central, and terminal region 

 of feeler. 



2. Right mandible of female, hinder aspect. ^ , 



r I m, molar area. 



3. Left mandible of male, front aspect. J 



4. Bight maxilla of male, hinder aspect ; </., galea, la., lacinia, p., palp. 



5. Portion of left maxilla of female, front aspect (galea, g. ; lacinia, la. ; 



and basal segment of palp, p.). 



6. Bight half of labium of female, p., palp. 



Magnification of figs. 1-6 = 36. 



7. Sensory spines from tip of labial palp. 



Magnification = 250. 



