426 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XVII. 



metallic-looking flat beetle to be found upon roses), where the elytra are 



joined together down the centre they are merely lifted up ; when the 



a FIG. 88. — Undersurface of a beetle. (Legs and 



antenna of one side and some parts of 

 mouth removed.) A, antenna ; -B r 

 mandible; C, labrum ; D, ligula ; E, 

 paraglo9sa ; F, labial palp ; G, inner 

 lobe of maxilla ; H, outer lobe of 

 maxilla ; I, maxillary palp ; K,, 

 mentum ; L, gena,; M, gula ; N, buc- 

 cal fissure ; V, plates of ventral seg- 

 ments. 1, Prosternum ; 2, prosternal 

 episternum ; 3, prosternal epimeron y 



4, anterior and middle coxal cavities - r 



5, inflexed side of pronotum ; 6, me- 

 sosternum ; 7, mesosternal episternum;. 

 8, mesosternal epimeron ; 9, metaster- 

 num ; 10, posterior division of meta- 

 sternum or ante-coxal piece ; 11, me* 

 tasternal episternum ; 12, metasternal 

 epimeron ; 13, epipleuron or inflexed 

 margin of elytron ; 14, ventral or 

 ambulatory setae ; 15, trochanter; 16, 

 posterior coxa ; 17, femur ; 18, tibia ; 

 19, tarsus. (Modified from Lecoute 

 and Horn.) 



elytra are absent, as occurs in some beetles ( Tenebrionidce, &c), there are 

 no lower wings present. The wings proper in beetles correspond to the 

 posterior or lower pair in other Insects. The nervures or veins in the 

 lower wing are broken up to allow of their being folded up under the 

 wing covers (c. f. left lower wing in Fig. 87). The number of tarsal 

 joints present varies from 2 — 5. One may be hidden and is only seen 

 on dissecting. For classification purposes only those visible are counted. 

 Some of the tarsal joints may be bi-lobed ; they are set with a spongy 

 felt- work of hair to help the insects to -walk about on plants. Only 5 — & 

 segments of the abdomen are visible. There is often a considerable dif- 

 ference in the sexes amongst beetles. There may be • either an increase 

 in size of the antennte in the males or an enlargement of the interior 

 tarsi; occasionally the number of joints of the tarsi vary in the two. 

 The only music produced is chirping or squeaking by rubbing two files 

 together. Phosphoretic organs are present in glow-worms and fire-flies. 

 These consist of masses of cells connected with a fatty body and are 

 freely supplied with air. The light produced is caused by the oxidation 

 of proteid matter. Thase organs are situated on the abdomen. 



