14 Miss Anna J. Reillj on 



1904. — SiLVESTRi, F. " Nuovi Generi e Specie di Macbilidse." Eedia, 



vol. ii. 

 1910. — Vkrhoeff, K. W. " Ueber Felsensprinf^er, Machiloidea, 4 Auf- 



satz : Systematik uiid Ortboniorpliose." Zool. Anzeiger, xxxvi. 



EXPLANATION OF THE PLATES. 

 Plate I. 



Structural details of Tetvohiiis vectensis. 



Fig. 1. Lateral (right) view of insect, $. X 12. 



Fig. 2. Diagrain showing shapes and positions of compound eyes {e), 



lateral ocelli (o), and median ocellus {mo). X 30. 

 Fig. 3. Right mandible of female, hinder aspect, c, condyle; «, apex ; 



ni, molar area. X 02. 

 Fiq. 4. Terminal region of same mandible, a, apex ; m, molar area. 



X liM. 

 Fig. 5. Left maxillula, hinder aspect. /, lacinia ; g, galea; p, palp. 



X 124. 

 Fig. 6. Eight maxilla of female, hinder aspect, c, cardo ; sf, stipes ; 



/. lacinia ; g, galea ; p, palp. X 62. 

 Fig. 6 a. Head of lacinia of same maxilla, showing apex (a), "brush" (i), 



and acute processes (c and d}. X 280. 

 Fig. 7. Labium of female. m, submentum; /, mentum ; p, palp. 



X 02. 

 Fig. 7 A. Sensory spines from apex of labium, x 280. 



Plate 11. 



Structural details oi Petrobius vectensis (continued). 



Fig. 1. Eighth abdominal segment, S , ventral aspect, sc, subcoxa ; 



st, stylet : s, sternum. X 40. 

 Fig. 2. Ninth abdominal segment, S , ventral aspect, se, subcoxa ; 



g, gonapophysis ; j^, penis ; st, stylet. X 40. 

 Fig. 3. Fifth abdominal segment, S, ventral aspect. s, sternum; 



sc, subcoxa ; ve. exsertile vesicles ; st, stvlet ; in, muscles. 



X 40. 

 Fig. 4. Eighth abdominal segment, $ , ventral aspect, sc, subcoxa ; 



st, stylet ; o, process of ovipositor. X 40. 

 Fig. 5. Ninth abdominal segment, $ , ventral aspect, sc, subcoxa ; 



st, stylet ; o, process of ovipositor. X 40. 



Plate 111. 

 Structural details of Petromachilis longicornis. 



Fig. 1. Lateral view of insect, 5 (body-length 10 mm.), x 6. 



Fig. 1 A. Two basal segments of antenna. X G'2. 



Fig. 1 B. Segments from about middle of antenna, showing grouping, 



X 62. 

 Fig. 2. Diagram showing .shape and positions of compound eyes (e), 



lateral ocelli (o), and median ocellus {mo). X 62. 



