248 Forty-fourth Report on the State Museum 



verse basal tubercle; joints 1-3 clavate; joint 1 about twice as long as 

 its width at tip; joint 2 one-fourth longer than joint 1; joint 3 as 

 long as joint 1, slightly and obliquely produced at its lower apical 



angle; joint 4 somewhat 

 shorter than joint 3, acu- 

 minate at tip ; labrum a 

 little longer than the cly- 

 peus, slightly narrowing 

 anteriorly, sides rounded, 

 anterior margin truncate 

 and armed with long stiff 

 bristles; upper surface 

 rugosely punctate. Man- 

 dibles nearly as long as 

 the width of the clypeus, 

 outer surface near base 

 coarsely cribrate and fur- 

 nished with two longi- 

 tudinal carinse, the slop- 

 ing inner surface and tip 

 smooth; edge of scissorial 

 part with three obtuse 

 teeth, the terminal one 

 -^/^ large and triangular, the 

 . middle one smaller but 

 also triangular, the basal 

 one rectangular, the three 

 teeth as well as the man- 

 ducatorial tooth larger on 

 the left than on the right 

 mandible; left manduca- 

 torial tooth quite promin- 

 ent at the anterior edge 

 and forming a right angle 

 with the scissorial surface; 

 right manducatorial tooth 

 with its anterior edge not prominent, under surface of scissorial 

 part opaque at tip, smooth and shining toward the base; stridulatorial 

 surface about three and one-half times longer than wide at middle, 

 the ridges becoming finer and shorter towards the apex. Lobes of 

 maxillae connate on the under (outer) side, except that there is a 

 shallow, smooth dividing furrow at tip ; on the upper (inner) side 

 the dividing suture is distinct throughout ; both lobes are on 

 either side covered with long yellow spines arising from little tuber- 

 cles; the outer lobe terminates in a stout thorn, inner lobe at tip with 

 three closely set triangular teeth; stridulating teeth on inner surface 

 not placed on a distinct ridge and consisting of six larger and two 

 or three very small and indistinct teeth; maxillary palpus decidedly 

 longer than the outer lobe, three-jointed, first joint distinctly clavate 

 and twice as long as its width at base, second joint as long as the 

 first and very slightly clavate, third joint narrower but one-fifth 

 longer than the second, subacuminate at tip. Mentum and lingua on 



Fig. 10.— Larva of the Rhinoceros beetle, Dynastes 

 TiTTUS, in natural size, with its mandibles enlarged' 



