1888. J NEW-YORK MICROSCOPICAL SOCIETY. 145 



THE BEETLE, ZOPHERUS MEXICANUS, SOL., 

 CUTTING METAL. 



BY F. W. DEVOE. 

 {Read May ^th, 1888.) 



The beetle, to which your attention is directed, is Zophert/s 

 inexicanus, Sol, a native of Central America, where it is popu- 

 larly known as "Makeche." Specimens average in length 

 from 4.5 to 5 centimetres, and in width from 1.5 to 2 centi- 

 metres. The thorax and elytra are yellowish gray, this color 

 being due to a coating of scales, which may be scraped away, 

 when the underlying normal black color will appear. The 

 dorsal surface is marked by many knobs arranged in lines, and 

 more prominent in the middle than at the sides. The general 

 color of the under surface and of the legs is black, but this is 

 more or less concealed in numerous places by the yellowish 

 scales before mentioned. The head is retracted as far as the 

 eyes into the pro-thorax. The antennae are nine to eleven 

 jointed, the outer two or three joints being connate, and, when 

 at rest, the antenna lie in two deep grooves on the under 

 surface of the pro-thorax. 



The character is indicated by the structure. A slow, de- 

 liberate walker — it never flies, for its hind wings are not 

 developed, and it never hurries. A lover of darkness — it 



Explanation of Plate 13. 



Fig. 1.— Dorsal aspect of the head of Zopherus mexicanus : I, labrum ; p, palpus; 

 c, clypeus ; e, eye ; a, antenna. 



Pig. 2.— Inner face of the labrum : b, fringing bristles ; m, insertion of muscles ; h, 

 deep hinge, with insertion of muscles, joining to clypeus. 



Fig. 3. — Ventral aspect of the head : I, labrum ; p, palpus ; m d, mandible ; I i, lab- 

 ium ; ni X, maxilla ; ni t, mentum ; a, antenna ; t h, thorax. 



Fig. 4. —Ventral aspect of the left maxilla with its palpi : ep, external palpus ; ip, 

 internal palpus. 



Fig. 5.— Inner face of the labium : b, bristles of tongue-groove ; m, insertion of 

 tongue muscles ; h, hinge, connecting the labium with the mentum. 



Fig. 6.— Longitudinal-vertical section of the head : th, thorax, c, clypeus, I, labrum ; 

 m d, mandible ; I i, labium ; m m, m m, muscles of the mandible ; tu h, 

 m h, muscles, moving the head on the thorax ; o, oesophagus. 



Pig. 7.— Ventral aspect of the right mandible : e, cutting edge ; c d, double headed 

 pivot, or condyle ; ni m, insertion of the muscles. 



Fig. 8. — External, lateral aspect of the right mandible : h, the hinge ; c, the condyle ; 

 1, 2, direction of cutting movement. 



