SIR JOHN LUBBOCK ON THE ANATOMY OP ANTS. 153 



Plate XI. 



Fig. 1. Vertical and longitudinal section through the prothorax of Lasius flavus. x 125. 



H, posterior wall of head; B, pronotum; P, propectus; Z, membrane connecting the 

 head and the pronotum; Z\ membrane connecting the head and the propectus; L, base 

 of leg cut short; An, antefurca. Muscles:— a, first, and a\ second elevator of the head; 

 b, first, and b\ second depressor of the head ; c, first rotator of the head ; d, fourth, and d\ 

 fifth rotator of the head; e, protractor of the head; /, elevator of antepectus; i, second 

 muscle of anterior leg ; /, fifth ditto. 

 Fig. 2. Longitudinal and vertical section through the thorax of Lasius flavus. x 125. 



H, posterior part of head; Pr, prothorax ; Mes, mesothorax ; Met, metathorax; C, anterior 

 plate of propectus; T, posterior plate of propectus; G l , first, G\ second, G\ third, and G\ 

 fourth thoracic ganglion ; gl, thoracic salvary gland ; Sjr, second, and Sp 3 , third spiracle ; 

 Z, membrane connecting the head and the pronotum. Muscles :— a, first, a\ second elevator 

 of the head ; b, first depressor of the head; c, first, d, fourth, and d\ fifth rotator of the head ; 

 /, elevator of antepectus ; i, second muscle of anterior leg ; /, fifth muscle of anterior leg ; m, 

 depressor, and n, elevator of prothorax; q, third, and r, fourth muscle of middle leg; u, first! 

 and u\ second elevator of abdomen ; v, first depressor of abdomen ; w, first rotator of "abdomen \ 

 x, first muscle of posterior leg. 

 Fig. 3. Glandular organ at base of prothorax in Myrmica ruginodis. L, upper portion of coxa of 



anterior leg. x 200. 

 Fig. 4. Vertical and longitudinal section through the thorax of Lasius flavus. x 125. 



Pr, pronotum; P, propectus; Sp 1 , first, Sp"-, second, and Sp 3 , third spiracle; U, base of 

 anterior leg ; L s , base of middle leg ; L 3 , base of posterior leg ; Cx, coxa. Muscles :— c, first, c\ 

 second, and e 2 , third rotator of the head ; /, elevator of antepectus ; h, first, i, second, k, fourth' 

 and /, fifth muscle of anterior leg; m, depressor of prothorax; o, 1st muscle of middle leg. 

 Fig. 5. Thorax of Lasius flavus, seen from above and somewhat flattened out. The external hairs are 

 omitted, x 125. 



Pr, prothorax; Mes, mesothorax; Met, metathorax; Sp 1 , first, and Sp 3 , third pair of 

 spiracles; Z, membrane connecting the thorax with the head; An, antefurca; Sgl, site of the 

 posthoracic glands. Muscles :— a, first, and a\ second elevator of the head ; c, first rotator of 

 head; e, protractor of head; /and f, the two elevators of the antepectus; g, depressor of 

 antepectus ; /, fifth muscle of anterior leg ; m, depressor, and n, elevator of prothorax ; o, first 

 muscle of the middle leg; u, first elevator of abdomen; w, first rotator of abdomen; x, first, 

 y, third muscle of posterior leg. 

 Fig. 6. Longitudinal and horizontal section through the prothorax of Lasius flavus. x 125. Seen from 

 below. 



P, wall of the propectus ; B, wall of the pronotum ; Z\ membrane connecting the pro- and 

 medipectus ; X, processes of the propectus ; W, processes of the head ; G\ first ganglion ; 

 An, antefurca. Muscles :— b, first depressor of the head; c\ c 2 , cut ends of the rotators of 

 the head ; d, d\ rotators of head ; g, cut ends of depressor of antepectus. 

 Fig. 7. Section through the prothorax at a rather lower level than the preceding, x 125. 



P, wall of the propectus; B, wall of the pronotum ; Z\ membrane connecting the pro- and 

 medipectus; X, processes of the propectus; W, processes of the head; G 1 , first ganglion ; 

 G 2 , second ganglion ; L, base of the leg ; An, antefurca. Muscles :— c 1 , second, and c 2 , third 

 rotator of the head ; g, depressor of antepectus ; h, first, k, fourth, and /, fifth muscle of anterior 

 leg (part of these being cut across). 



