126 HORTENSE BUTLER. 



The Gomphinse labia differ comparatively little from those of 

 ^schninae. In a typical specimen, Gomphus vulgatissimus (PI. VI, 

 Fig. 1), the lateral lobes are perha{)s larger in proportion to the 

 raentum than is the case with the ^schninse, but the general effect 

 is very similar. . The inner edges of the lateral lobes exhibit a 

 series of six or eight small blunt teeth. The ligula is in this case 

 entire, its margin perfectly straight, and covered with hairs. In 

 Phyllogomphus ethiops (PI. VI, Fig. 1 a and e) the teeth on the 

 lateral lobe are more numei'ous and somewhat sharper than in the 

 other, and the border of the ligula is V-shaped and covered with 

 small spine-like teeth. 



Gomphua dilatatus has the ligula (PI, VI, Fig. 1/) concave and 

 bordered with hairs. OphiogompJms severus (PI. VI, Fig. 1 g and c) 

 shows a blunt end hook while the teeth on the inner margin of the 

 lateral lobes are obsolete, and are represented by chitinized spots. 

 Aphylla sp. ? (PI, VI, Fig. 1 b) has a slightly incurved end hook, 

 while the teeth on the inner edge of the lateral lobe are four in num- 

 ber and are large and sharp. The ligula is slightly convex and 

 bordered with hairs. An undescribed Gomphid from Brazil (PI. 

 VI, Fig. 1 li) exhibits a very singular end hook ; it is quite long and 

 rather sharp and bends abruptly downward toward the ligula, while 

 the tip is again slightly elevated. The lateral lobe is quite devoid 

 of teeth. The ligula of Macrogoviphus sp. ? (PI. VI, Fig. Id) has 

 a V shaped cleft in the center of the prominent ligula, and a sloping 

 border on either side is covered with hairs. 



CORDUL.KGASTER and TACHOPTERYX. 



The labium of Cor duleg aster maculutus, the lateral lobes of which 

 are deeply concave, as in the Libellulidie, exhibits a series of large 

 triangular teeth along the distal edges of the lateral lobes. These 

 teeth are sharp but very irregular in size : somB of them are carried 

 over into the adult stage. Tiie movable hook is small in comparison 

 with the rest of the lateral lobe. A series of five setre appear just 

 within the outer edge of each lobe. The ligula has in the center a 

 marked elevation with a small cleft in it. The mentum has a group 

 of about ten raptorial setye on either side of the center. 



Tachopterijx thorei/l shows a lateral lobe with a well developed 

 movable hook but a verv blunt end ; the inner edge is covered with 



