EXTERNAL ANATOMY. 55 



angles to the cardo and parallel to the long axis of the 

 head. It is movable towards and away from the median 

 line. The maxillary palpus {mx. p) is carried upon the 

 outer angle of the stipes, and is made up of two short and 

 three long joints. The lacinia {lac), the toothed black- 

 tipped cutting portion of the maxilla, is carried upon the 

 inner margin of the distal end of the stipes T\\q galea iga), 

 or soft, brown, spoon-shaped portion of the maxilla, is car- 

 ried upon the outer angle of the stipes and bends around 

 in front of the lacinia. The illustration, (Fig. 27), shows 

 the different parts described above. 



The Thorax. — To study the thorax, the legs and wings 

 shoidd be removed. It will be seen that the thorax is made 

 up of three segments, each of which bears a pair of legs. 

 These three segments are known as the prothorax [pro), 

 mesothorax {meso), and nietathorax (meta). The pro- 

 thorax, (Fig. 28), has the sides and dorsal surface covered 

 by a large, sun-bonnet shaped piece, 

 < lr^__ .^ the pronotum (n). The dorsal por- 



tion of the pronotum is prolonged 



f^' backwards along the median line and 

 yl'^^. partially overlaps the second division 

 or mesothorax. The anterior portion 

 of the pronotum is crossed by three 

 ^"■o-f'^^sF grooves or sutures, which divide it 



FIG. 28 -Lateral view into four immovably uuitcd picccsj the 

 of the prothorax of Meian- fl^g^- of thcsc forms the antcHor mar- 

 op/US bivittatus. Original. . „ ^ i • ii i 1 



gm oi the pronotum, and is called the 

 prothoracic prescutum {p. sc); the second is the prothoracic 

 scutum {sc)\ the third the prothoracic scutellum (scl), and 

 the last the prothoracic postscutellum (p.sel). The ventral 

 portion of the prothorax, (Fig. 29), is formed by a slender, 

 movable sterum {st), w^hich connects the sides of the prono- 

 tum with each other. On the median line it carries, in this 

 species, a large club-shaped spine {pro. sp). Near the outer 

 ends of the sternum are the fossae for the attachment of 



